Donald Trump has called a National Emergency to fund his border wall. Can he make a deal?

US President Donald Trump has branded Democratic opponents “crazy” and guilty of overreach in a frenzied response to a huge new Democratic-led probe of his alleged crimes.

In a searing burst of tweets, the president said the House Judiciary Committee investigation launched on Monday was “the greatest overreach in the history of our Country.”

“The real crime is what the Dems are doing, and have done!” he said.

Another tweet labelled Democratic leaders “stone cold CRAZY.”

“PRESIDENTIAL HARASSMENT!” said another.

Trump’s exclamation mark and capital letter-laden outburst indicated rising temperature in a White House under assault from multiple directions.

Democrats, who took control of the House of Representatives last November, suspect Trump of a slew of potentially impeachable offences, including obstruction of justice and abuse of office.

The powerful judiciary committee is demanding information from 81 Trump-connected individuals and entities, including his sons.

The greatest overreach in the history of our Country. The Dems are obstructing justice and will not get anything done. A big, fat, fishing expedition desperately in search of a crime, when in fact the real crime is what the Dems are doing, and have done! — Donald J. Trump (@realDonaldTrump) March 5, 2019

Now that they realize the only Collusion with Russia was done by Crooked Hillary Clinton & the Democrats, Nadler, Schiff and the Dem heads of the Committees have gone stone cold CRAZY. 81 letter sent to innocent people to harass them. They won’t get ANYTHING done for our Country! — Donald J. Trump (@realDonaldTrump) March 5, 2019

PRESIDENTIAL HARASSMENT! — Donald J. Trump (@realDonaldTrump) March 5, 2019

Republican Approval Rating just hit 93%. Sorry Haters! MAKE AMERICA GREAT AGAIN! — Donald J. Trump (@realDonaldTrump) March 5, 2019

The new front opened just as Trump braces for the results of an independent probe into his dealings with Russia by special prosecutor Robert Mueller.

Rumours that Mueller is close to ending his two-year investigation have set Washington on edge.

Debate over whether the prosecutor’s findings should be made immediately public is already underway, with Democrats warning that attempts at a cover-up by the White House could lead them to subpoena Mueller to testify.

Trump’s response to the pressure has been consistent with his longtime playbook: to insult accusers, admit no weakness, and rely on backing from his ultraloyal political base.

Polls show that the president’s support among Republican voters remains strong, even if Democratic voters are just as convinced in opposition.

However, cracks in Republican support at the top echelons of the party have appeared.

When the Democratic majority in the House voted to overturn Trump’s controversial use of emergency powers to force funding for US-Mexico border wall construction, that was expected.

However, this week four Republican senators have broken ranks to join their Democratic opponents in the upper house, meaning the motion can pass there too.

Trump will likely be able to brush aside that rebuke by using the first veto of his presidency. However, the fact that he has lost the guaranteed backing of his party in the Senate could point to trouble ahead.

In Trump’s combative vision of politics, the looming probes are not all bad news.

Already the White House is framing the Democratic onslaught as symptomatic of leftist radicalism supposedly threatening the country.

Trump has made the spectre of far-left socialism a growing part of his 2020 re-election campaign, even claiming that Democrats want to replicate the violent chaos underway in Venezuela.

“Democrats are harassing the President to distract from their radical agenda of making America a socialist country, killing babies after they’re born, and pushing a ‘green new deal’ that would destroy jobs and bankrupt America,” Trump spokeswoman Sarah Sanders said late on Monday.

Trump’s other main angle of attack has been to dismiss the validity of the Mueller probe, which he has repeatedly dubbed a “witch hunt” and “phony” in hopes of reducing its credibility.

But in an indication that the president’s rhetorical bombshells risk misfiring, former Trump White House lawyer Ty Cobb went public on Tuesday with a surprising defence of Mueller, calling him an “American hero.”

“I don’t feel the investigation is a witch hunt,” Cobb told ABC News podcast The Investigation.