ELKO, Nevada (AP) — Donald Trump, the leading Republican presidential candidate, is trading political blows with his rivals in Nevada, where voters on Tuesday make their choice for the party’s nominee in the November general election.

The still-large field of Republican candidates has produced a fiery presidential nominating contest for the top spot on the ballot ahead of November’s presidential election.

In the Democratic race, former Secretary of State Hillary Clinton is regaining momentum against Vermont Sen. Bernie Sanders, a democratic socialist who had proved himself a much tougher challenger than expected ahead of Saturday’s South Carolina primary.

Trump, an unorthodox candidate and billionaire New York businessman, delivered a broadside against competitor Ted Cruz, telling thousands in Las Vegas on Monday he thinks the Texas senator "is sick."

"There’s something wrong with this guy," said Trump.

Trump continued to make headlines for his off-the-cuff statements.

At a rally in Las Vegas, the billionaire real estate mogul, said he’d like to punch a protester in the face. He lamented the "old days" when he said the man would have been taken out of the event on a stretcher.

For his part, Cruz spent significant time trying to explain the ouster of his spokesman for tweeting a story that falsely accused fellow Republican hopeful Marco Rubio, a Florida senator, of insulting the Bible. And when the candidates weren’t directing their fire at each other, they used scattered appearances on the eve of Tuesday’s caucuses to assail Clinton, a former New York senator as well as the wife of former President Bill Clinton.

Rubio, who edged out Cruz for second place in the Republican South Carolina primary on Saturday, was high on the Cruz’s list of talking points — even if the Texan would have preferred otherwise. Addressing the firing of spokesman Rick Tyler, Cruz told reporters he had no choice but to dismiss his aide.

"We are taking the high road," Cruz said.

Tyler did not return telephone, text or email messages left by The Associated Press seeking comment.

It’s not the first time that Cruz’s campaign has been accused by rivals of using questionable tactics. Cruz apologized to Republican Ben Carson earlier this month after his campaign promoted a news story suggesting that Carson was getting out of the race. Cruz’s campaign has also acknowledged creating a website that used a computer program to create a fake picture of Rubio shaking hands with President Barack Obama.

Meanwhile, establishment heavyweights continued to back Rubio, with many saying they see him as the candidate who can unite a disharmonious Republican Party. Arkansas Gov. Asa Hutchinson and Utah Sen. Orrin Hatch were the latest to endorse the Floridian. South Florida’s three Cuban-American members of Congress also said that they shifted their support to Rubio, having previously backed Jeb Bush, who dropped out of the campaign after the South Carolina primary.

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