Donald Trump described Democrats as “unhinged” and “an angry mob” during a campaign pitch to voters in Iowa, four weeks ahead of the midterm elections.

The president told the arena crowd of roughly 9,000 people that Democrats would destroy people’s businesses, provide sanctuary to murderous immigrant gangs and plunge the nation into “poverty” and “chaos”.

“The Democrats have become too extreme and they’ve become, frankly, too dangerous to govern,” Mr Trump said. “They’ve gone wacko!”

His 76-minute speech, held at a border town along the Missouri River, was a preview not only of his campaign blitz over the next 28 days, but also of his own re-election push that will begin in earnest soon after the midterms.

The president said Fred Hubbell, the Democrat challenging Iowa’s governor, Kim Reynolds, intends to “massively raise your taxes”, “take away your ethanol” and “devastate your farms and businesses”.

Mr Trump called Democrats “Dems”, which he pronounced as “Dims” – an apparent play on their intelligence.

He said he picked up the nickname from “the great Lou Dobbs”, the Fox Business Network host.

Mr Trump mentioned more than six other Fox News Channel stars at the rally, including Sean Hannity, Tucker Carlson, Laura Ingraham and Jeanine Pirro.

Donald Trump UK visit: protests, placards and putting Show all 100 1 /100 Donald Trump UK visit: protests, placards and putting Donald Trump UK visit: protests, placards and putting Britain's Prime Minister Theresa May and US President Donald Trump walk to a joint news conference holding hands Reuters Donald Trump UK visit: protests, placards and putting People march holding anti-Trump signs in Edinburgh while the US. President is visiting Trump Turnberry Luxury Collection Resort in Scotland Getty Donald Trump UK visit: protests, placards and putting President Donald Trump and first lady Melania Trump depart from Glasgow Prestwick Airport REUTERS Donald Trump UK visit: protests, placards and putting Trump on the back Getty Donald Trump UK visit: protests, placards and putting President Donald Trump waves whilst playing a round of golf at Trump Turnberry Luxury Collection Resort Getty Images Donald Trump UK visit: protests, placards and putting Donut TrumpScotland United Against Trump demonstrators gather at the Scottish Parliament in Edinburgh PA Donald Trump UK visit: protests, placards and putting Donald Trump plays a round of golf at Trump Turnberry Getty Images Donald Trump UK visit: protests, placards and putting People march holding anti-Trump signs Getty Donald Trump UK visit: protests, placards and putting US President Donald Trump plays a round of golf on the Trump Turnberry resort in South Ayrshire, where he and first lady Melania Trump are spending the weekend. PRESS ASSOCIATION Photo. Picture date: Saturday July 14, 2018. See PA story POLITICS Trump. Photo credit should read: Andrew Milligan/PA Wire Andrew Milligan PA Donald Trump UK visit: protests, placards and putting Trump waves form golf course Getty Donald Trump UK visit: protests, placards and putting TURNBERRY, SCOTLAND - JULY 14: Scottish stand-up comedian Janey Godley gives a high-five to a police officer as she holds a sign in protest on the beach outside near Trump Turnberry Luxury Collection Resort during the U.S. President's visit to the United Kingdom on July 14, 2018 in Turnberry, Scotland. The President of the United States and First Lady, Melania Trump on their first official visit to the UK after yesterday's meetings with the Prime Minister and the Queen is in Scotland for private weekend stay at his Turnberry. (Photo by Leon Neal/Getty Images) Leon Neal Getty Images Donald Trump UK visit: protests, placards and putting Trump goes for a stroll Getty Donald Trump UK visit: protests, placards and putting Trump blimpA giant balloon depicting US President Donald Trump as an orange baby is launched as protesters gather in the Meadows, after taking part in the Scotland United Against Trump march through the streets of Edinburgh AFP/Getty Donald Trump UK visit: protests, placards and putting U.S. President Donald Trump drives his golf buggy REUTERS Donald Trump UK visit: protests, placards and putting A Greenpeace protester flying a microlight passes over Donald Trump's resort in Turnberry PA Donald Trump UK visit: protests, placards and putting President Donald Trump and first lady Melania Trump look at the media during their arrival on Air Force One at Glasgow Prestwick Airport in Scotland AP Donald Trump UK visit: protests, placards and putting Scotland United Against Trump demonstrators gather at the Scottish Parliament in Edinburgh PA Donald Trump UK visit: protests, placards and putting Security and police teams surround the perimeter of Trmup's golf course Getty Donald Trump UK visit: protests, placards and putting Scotland United Against Trump demonstrators PA Donald Trump UK visit: protests, placards and putting Teams of police officers patrol the beach outside near Trump Turnberry Luxury Collection Resort Getty Donald Trump UK visit: protests, placards and putting Pro-Trump supporters demonstrate outside the US Embassy in support of President Donald Trump's visit to the UK, in London EPA Donald Trump UK visit: protests, placards and putting Scottish Labour leader, Richard Leonard speaks to crowd PA Donald Trump UK visit: protests, placards and putting Ex-pat AFP/Getty Donald Trump UK visit: protests, placards and putting Demonstrators hold placards near the golf resort owned by US President REUTERS Donald Trump UK visit: protests, placards and putting Protesters wear orange face makeup Getty Donald Trump UK visit: protests, placards and putting Pro-Trump supporters demonstrate outside the US Embassy in London EPA Donald Trump UK visit: protests, placards and putting Trump protestors on the beach near to the Trump Turnberry resort PA Donald Trump UK visit: protests, placards and putting Protestors against the UK visit of US President Donald Trump near Aberdeen AFP/Getty Donald Trump UK visit: protests, placards and putting A mounted police officer patrols anti-Trump rally Getty Donald Trump UK visit: protests, placards and putting Trump supporter Bill McGibbon outside his cottage near to the Trump Turnberry resort in South Ayrshire PA Donald Trump UK visit: protests, placards and putting Trafalgar Square is filled with protesters against the UK visit of US President Donald Trump holding up placards as they take part in a march and rally in London on July 13, 2018. Tens of thousands of protesters demonstrated in London on Friday against US President Donald Trump, whose four-day visit to Britain has been marred by his extraordinary attack on Prime Minister Theresa May's Brexit strategy. / AFP PHOTO / Tolga AKMENTOLGA AKMEN/AFP/Getty Images TOLGA AKMEN AFP/Getty Images Donald Trump UK visit: protests, placards and putting Queen Elizabeth II and President Donald Trump inspect an honour guard at Windsor Castle Getty Images Donald Trump UK visit: protests, placards and putting Demonstrators on the 'Stop Trump' march through London, as part of the protests against the visit of US President Donald Trump to the UK. PRESS ASSOCIATION Photo. Picture date: Friday July 13, 2018. See PA story POLITICS Trump. Photo credit should read: Joe Giddens/PA Wire Joe Giddens PA Donald Trump UK visit: protests, placards and putting Queen Elizabeth II stands with US President Donald Trump and his wife, Melania, during their visit to Windsor Castle PA Donald Trump UK visit: protests, placards and putting Donald Trump walks ahead of Queen Elizabeth AP Donald Trump UK visit: protests, placards and putting LONDON, ENGLAND - JULY 13: Protesters take part in a demonstration against President Trump's visit to the UK in Trafalgar Square on July 13, 2018 in London, England. Tens of Thousands Of Anti-Trump protesters are expected to demonstrate in London and across the country against the UK visit by the President of the United States. Many people disagree with his policies that include migrant family separation, discrimination of transgender military personnel and changes to laws protecting women's sexual health. (Photo by Chris J Ratcliffe/Getty Images) Chris J Ratcliffe Getty Donald Trump UK visit: protests, placards and putting Donald and Melania Trump listen to the Coldstream Guards, play the US national anthem next to the Queen REUTERS Donald Trump UK visit: protests, placards and putting Protesters in Windor Getty Images Donald Trump UK visit: protests, placards and putting US President Donald Trump and first lady Melanie Trump are greeted by Queen Elizabeth II, during an arrival ceremony with the Guard of Honour at Windsor AP Donald Trump UK visit: protests, placards and putting Queen Elizabeth II waits to greet US President Donald Trump as he arrives by helicopter AFP/Getty Donald Trump UK visit: protests, placards and putting Ed Miliband joins the march Angela Christofilou Donald Trump UK visit: protests, placards and putting PM and President Getty Donald Trump UK visit: protests, placards and putting Protestors hold banners AP Donald Trump UK visit: protests, placards and putting UK meets US AFP/Getty Donald Trump UK visit: protests, placards and putting Protests at Trump visit Angela Christofilou Donald Trump UK visit: protests, placards and putting Trump and May Getty Donald Trump UK visit: protests, placards and putting Protests at Trump visit Will Gore Donald Trump UK visit: protests, placards and putting Protesters for the 'Stop Trump' Women's March gather in London AP Donald Trump UK visit: protests, placards and putting US President Donald Trump and Britain's Prime Minister Theresa May hold a joint press conference AFP/Getty Donald Trump UK visit: protests, placards and putting Donald Trump and Theresa May attend a press conference AFP/Getty Donald Trump UK visit: protests, placards and putting Demonstrators protest against the visit of U.S. President Donald Trump REUTERS Donald Trump UK visit: protests, placards and putting Prime Minister Theresa May walks with US President Donald Trump at Chequers Getty Donald Trump UK visit: protests, placards and putting Donald Trump UK protest Angela Christofilou Donald Trump UK visit: protests, placards and putting First Lady, Melania Trump, tries her hand at bowls Getty Donald Trump UK visit: protests, placards and putting US President and British Prime Minister at Chequers Reuters Donald Trump UK visit: protests, placards and putting Demonstrator in Black Lives matter T-shirt Angela Christofilou Donald Trump UK visit: protests, placards and putting Theresa May and Donald Trump enter Chequers REUTERS Donald Trump UK visit: protests, placards and putting Protestors wearing Donald Trump and Theresa May paper mache heads join the protest in Butler's Cross PA Donald Trump UK visit: protests, placards and putting First Lady, Melania Trump, looks on as Philip May tries bowls Getty Images Donald Trump UK visit: protests, placards and putting American Psycho poster Angela Christofilou Donald Trump UK visit: protests, placards and putting First Lady, Melania Trump, reacts as she tries her hand at bowls Getty Donald Trump UK visit: protests, placards and putting Donald Trump protest in London Angela Christofilou Donald Trump UK visit: protests, placards and putting Theresa May, Donald Trump with US ambassador to the United Kingdom Woody Johnson and British Foreign Secretary Jeremy Hunt at the start of the bilateral meeting at Chequers EPA Donald Trump UK visit: protests, placards and putting Melania Trump and Philip May wave flags REUTERS Donald Trump UK visit: protests, placards and putting Donald Trump is greeted by Theresa May AP Donald Trump UK visit: protests, placards and putting The US First Lady Melania Trump, helps children to make poppies PA Donald Trump UK visit: protests, placards and putting The handshake between Donald Trump and Theresa May AP Donald Trump UK visit: protests, placards and putting Demonstrators raise a six meter high effigy of Donald Trump Getty Donald Trump UK visit: protests, placards and putting Donald Trump stands alongside Theresa May after he arrived for talks at Chequers, her country residence in Buckinghamshire PA Donald Trump UK visit: protests, placards and putting A six-meter high cartoon baby blimp of Donald Trump hovers next to the statue of former Prime Minister Winston Churchill AP Donald Trump UK visit: protests, placards and putting First Lady, Melania Trump, accompanied by Philip May, meets schoolchildren and British Army veterans Getty Donald Trump UK visit: protests, placards and putting A lookalike of former British Foreign Minister Boris Johnson stands next to a person in a cage wearing a money suit and a mask of Donald Trump AP Donald Trump UK visit: protests, placards and putting Donald Trump gestures as he prepares to board Marine One to depart the US ambassador's residence Winfield House AFP/Getty Donald Trump UK visit: protests, placards and putting Demonstrators stand in front of a blimp portraying US. President Donald Trump, in Parliament Square REUTERS Donald Trump UK visit: protests, placards and putting The Prime Minister hosts President Trump and First Lady Melania at a black tie dinner with business leaders at Blenheim Palace AFP/Getty Donald Trump UK visit: protests, placards and putting The Prime Minister, accompanied by husband Philip, arrive with President Trump and First Lady Melania to a black tie dinner with business leaders at Blenheim Palace AP Donald Trump UK visit: protests, placards and putting The Prime Minister and President Trump are seen holding hands, not for the first time EPA Donald Trump UK visit: protests, placards and putting President Donald Trump pumps his fist during his arrival, with first lady Melania Trump, in Regent's Park AP Donald Trump UK visit: protests, placards and putting Demonstrators bang pots and pans as they gather at the US ambassador residence in Regent's Park PA Donald Trump UK visit: protests, placards and putting US President Donald Trump and US First Lady Melania Trump walk in the grounds of the US ambassador's residence Winfield House AFP/Getty Donald Trump UK visit: protests, placards and putting A demonstrator protests next to the specially erected fence surrounding the US ambassador's residence REUTERS Donald Trump UK visit: protests, placards and putting A motorcade arrives at Winfield House in London, the residence of American Ambassador to the to the Court of St James's PA Donald Trump UK visit: protests, placards and putting A presidential helicopter lands in the grounds of the US ambassador residence in Regent's Park PA Donald Trump UK visit: protests, placards and putting Protesters chant and wave placards during a demonstration outside Winfield House Getty Donald Trump UK visit: protests, placards and putting he Marine One helicopter carrying US President Donald Trump and First Lady Melania Trump flies past the BT Tower Getty Donald Trump UK visit: protests, placards and putting Protesters chant and wave placards during a demonstration outside Winfield House Getty Donald Trump UK visit: protests, placards and putting US President Donald Trump and First Lady Melania Trump disembark from Air Force One after arriving in the UK Reuters Donald Trump UK visit: protests, placards and putting US First Lady Melania Trump and US President Donald Trump are greeted by US Ambassador to the United Kingdom Woody Johnson AFP Donald Trump UK visit: protests, placards and putting US President Trump and Melania Trump leaving Stansted Airport PA Donald Trump UK visit: protests, placards and putting An honour guard stands to receive US President Donald Trump and US First Lady Melania Trump AFP/Getty Donald Trump UK visit: protests, placards and putting Donald and Melania Getty Donald Trump UK visit: protests, placards and putting US President Donald Trump and First Lady Melania Trump greet Secretary of State for International Trade Liam Fox on their arrival Getty Donald Trump UK visit: protests, placards and putting US Marine Corps Osprey aircraft taking off PA Donald Trump UK visit: protests, placards and putting Us President Donald Trump and First Lady Melania Trump disembark from Air Force One AP Donald Trump UK visit: protests, placards and putting US President Trump and Melania Trump arrive at Stansted PA Donald Trump UK visit: protests, placards and putting A giant 'Human Rights Nightmare' banner is unfurled by Amnesty International activists across the river Thames on Vauxhall Bridge to protest against the visit of US President Donald Trump AP Donald Trump UK visit: protests, placards and putting US President Donald Trump waves as he arrives in the UK PA Donald Trump UK visit: protests, placards and putting An armed police officier waits on the tarmac at Stansted Airport AFP/Getty Donald Trump UK visit: protests, placards and putting US President Donald Trump and Melania Trump arrive at Stansted Airport PA Donald Trump UK visit: protests, placards and putting Armed police await the arrival of US President Donald Trump at Stansted Airport REUTERS

Mr Trump claimed victory throughout – not only for the confirmation of Supreme Court Justice Brett Kavanaugh after a bruising nomination fight, but also for new trade deals, the falling unemployment rate and last December’s tax cuts.

“The only reason to vote Democrat is if you are tired of winning,” Mr Trump said.

He said the sexual assault allegations against Mr Kavanaugh were “a national embarrassment” and the product of a Democratic campaign to “destroy that man”.

“In four weeks, you will have a chance to render your verdict on the Democrats’ outrageous conduct,” Mr Trump said.

President Trump singled out senator Dianne Feinstein, ranking member on the Senate Judiciary Committee, and accused her of disclosing the identity of Christine Blasey Ford, who had written a confidential letter this summer detailing her claims against Mr Kavanaugh.

Ms Feinstein has denied that she or her staff leaked Ms Ford’s name to the press, but Mr Trump insisted she had.

“Did she leak that? One hundred per cent,” Mr Trump said. “I don’t want to get sued, so 99 per cent.”

The crowd burst into chants of “Lock her up!” – a Trump rally staple usually reserved for demeaning Hillary Clinton, Mr Trump’s 2016 Democratic opponent.

Moments later, the crowd again chanted “Lock her up!” – this time when Mr Trump invoked Ms Clinton in his remarks.

As his rally crowd called for the imprisonment of two Democratic politicians, Mr Trump said it was the Democrats who were the party of lawlessness.

“You don’t give power to an angry left-wing mob,” Mr Trump said, warning that if Democrats win congressional majorities next month they would “turn our country so fast into Venezuela.”

Donald Trump says 'no one more competent in the world' than Ivanka to do US ambassador job

President Trump also recounted his greatest hits against prominent Democrats.

He called senator Richard Blumenthal, a frequent cable-news critic of Mr Trump, “DaNang Dick” - a reference to the senator overstating his military service during the Vietnam war several years ago.

Mr Trump also singled out senator Elizabeth Warren for particular disdain.

He said Democrats “have gone so far left that they consider ‘Pocahontas’ a rational person”.

“No, it’s crazy! Elizabeth Warren. Oh, I hope she runs. We can finally get down to the fact as to whether or not she has Indian blood.”

President Trump added that “her mother says she has high cheekbones”.

Mr Trump said Ms Warren’s claims of Native American ancestry have given her unfair advantages in her career.

Ms Warren has said her claims of Native American ancestry are based on family lore. But a Boston Globe investigation last month found that her ethnicity did not help her advance in her law career.

Donald Trump says people who opposed 'great person' Brett Kavanaugh were 'evil'

Tuesday night’s event was the first of several “Make America Great Again” campaign rallies scheduled for this week.

President Trump plans to visit Erie, Pennsylvania, on Wednesday, and then rally supporters in Ohio and Kentucky on Friday and Saturday respectively. Last week, he headlined rallies in Tennessee, Mississippi, Minnesota and Kansas.

Mr Trump has already visited Iowa three times as president. He won the state by 9 per centage points in 2016.

But 56 per cent of Iowans now disapprove of his performance as president, while only 39 per cent approve, according to an Iowa Poll conducted last month.

Council Bluffs sits on Iowa’s western edge, across the Missouri River from Omaha, and Republican officials and candidates from both Iowa and Nebraska attended the rally.

There was a clear Nebraska tint to the audience, which at one point burst into chants of “Go, Big Red” – a reference to the University of Nebraska’s football team.

When President Trump asked attendees to cheer to identify their state of residence, the screams from Nebraskans were louder than those from Iowans.

Mr Trump used the event to announce that his administration will press forward with plans to promote the use of ethanol, in a move that could boost Republicans on the ballot across Midwestern states.

The announcement paves the way for year-round sales of E15, or fuel that is 15 per cent ethanol by volume. Currently sales of the fuel are prohibited during the summer months due to air pollution concerns.

“Today we are unleashing the power of E15 to fuel our country all year long,” Mr Trump said, to big cheers from the crowd.

He noted he “made that promise to you during the primaries, remember? Promises made, promises kept”.