Trump doubles down despite campaign violence

Donald Trump doubled down Sunday on his claim that "thugs" -- not his heated rhetoric -- are to blame for spiraling tensions at his rallies two days before a crucial round of voting in the 2016 White House race.

The Republican presidential frontrunner hit the campaign trail determined to build an insurmountable lead in this week's key nomination contests, as rivals on both sides of the political divide warned his inflammatory language was inciting violence.

Dubbed "Super Tuesday 2" by US media, the latest key date in the run up to November's general election will see Democratic and Republican contests in the states of Florida, Ohio, Illinois, Missouri and North Carolina.

Republican Presidential candidate Donald Trump speaks at a rally at Synergy Flight Center on March 13, 2016 in Bloomington, Illinois ©Tasos Katopodis (AFP)

Trump this weekend jetted on his private plane between rallies in the delegate-rich states, as his Republican rivals Texas Senator Ted Cruz, Florida Senator Marco Rubio and Ohio Governor John Kasich also ramped up campaigning on the ground.

In Cincinnati, Ohio, hundreds lined up in the early morning to see the candidate despite a persistent drizzle -- while demonstrators also massed ahead of the event, chanting "Build bridges, Not walls" and "No Trump no KKK, no fascist USA."

Some Trump supporters verbally challenged the protesters, but there was no repeat of the scenes that erupted in Chicago late Friday where a planned rally had to be cancelled because of unrest.

Still the tensions were palpable as Secret Service or police officers completely surrounded Trump's stage in Cincinnati, a day after a protester burst on stage at another event in the Midwestern state.

A protester holding a Sanders sign above his head interrupted the candidate before being escorted out, to a loud cheer from the crowd.

"It's fine," Trump said. "In certain ways, it makes it more exciting."

Trump supporter Adam Ward, 34 -- a military veteran from Ohio who served in Iraq in 2003 -- believed the anti-Trump protesters were actually helping the candidate.

"It enrages people that don't agree with Bernie Sanders," he said of the Democratic presidential candidate who Trump accuses of instigating the protests. "I probably wasn't going to come to this until I saw Chicago being shut down. It irritated me."

Friday's troubles in Chicago saw ardent Trump supporters and opponents come to blows, after dozens of campaign stops where Trump has berated his opponents and encouraged the crowd to verbally and physically mistreat protesters.

The billionaire's invective also has targeted journalists, the disabled, women, Muslims, Hispanics and other minorities -- often to raucous approval from thousands of chanting partisans.

But as with each new controversy swirling around him, Trump seemed unscathed with polls suggesting he remained on a glide path toward the party nomination heading into Tuesday's make-or-break round of voting.

- 'Lose our republic' -

Politicians across the spectrum are increasingly alarmed at the divisiveness and erosion of civility seen in the campaign and have called on Trump to tone down his rhetoric, saying he is exploiting anger among the electorate.

Senator Rubio, who is trailing in third place and like Kasich faces a do-or-die test in Tuesday's vote in his home state, called Trump's language "dangerous."

"If we reach a point in this country where we can't have a debate about politics without it getting to levels of violence and anger," he told CNN, "we're going to lose our republic."

An anti-Donald Trump super-political action committee broadcast a television advertisement on Sunday airing clips of Trump saying "I'd like to punch him in the face," and similarly harsh statements directed against protesters.

But Trump has rejected out of hand any suggestion that his rhetorical excesses have created a climate of violence.

"I don't accept responsibility. I do not condone violence in any shape," he told NBC on Sunday, repeating his assertion that agitators -- mostly linked to Sanders -- were responsible for tensions spilling over.

- Video hoax -

"Bernie Sanders is lying when he says his disruptors aren't told to go to my events. Be careful Bernie, or my supporters will go to yours!" he taunted on Twitter.

Sanders denied his campaign had directed supporters to protest at Trump rallies.

"Trump's words must be taken with a grain of salt because I think as almost everyone knows, this man cannot stop lying about anything," the Vermont senator said to CNN. "People are catching on to Donald Trump. That's why he's getting reckless."

Trump appeared to condone one particularly striking act of violence, when a demonstrator was sucker-punched as he was led by police from a rally last week in North Carolina, by saying his staff would look into paying the belligerent supporter's legal bills.

On Saturday after a demonstrator tried to rush on stage at a rally in Dayton, Ohio, the candidate claimed the man was linked to the Islamic State group -- an assertion that he refused to disown despite it becoming apparent it was based on a crude video hoax.

"What do I know about it?" he told NBC. "All I know is what's on the Internet."

Campaign buttons for sale outside a rally for Republican presidential hopeful Donald Trump March 13, 2016 in West Chester, Ohio ©Brendan Smialowski (AFP)

A supporter of Bernie Sanders holds up a placard during a Trump rally at the International Exposition Center in Cleveland, Ohio ©Brendan Smialowski (AFP)

US Republican presidential hopeful Marco Rubio is facing a make-or-break test in upcoming nominating races ©Rhona Wise (AFP/File)