Ex-GOP hopeful Chris Christie backs Trump in White House race

Mr Christie, speaking alongside Mr Trump in Fort Worth, Texas, said the real estate mogul had the best chance of beating Democrat Hillary Clinton in the November 8 presidential election.

Marco Rubio ramped up his attacks on Donald Trump Friday, calling the GOP presidential front-runner a “con artist”, mocking his misspelled tweets and suggesting he wet his trousers during the latest debate because he was so rattled.

Cruz and Rubio are looking ahead to Tuesday’s primary contests differently.

Cruz told Tapper he hopes “those 65% of Republicans that don’t think Donald can beat Hillary will continue to unite behind our campaign”.

Once on stage, Trump even appeared off-balance when Rubio questioned whether Trump would have been “selling watches in Manhattan”, had not been his inheritance of a vast fortune.

Former secretary of state Hilary Clinton is battling USA senator Bernie Sanders of Vermont for the Democratic nomination.

Trump’s unorthodox candidacy has shaken the Republican Party and has drawn increasingly vehement criticism from his rivals.

Marco Rubio released summaries of his tax filings from the last five years Saturday, showing that he has received a regular senator’s income of $176,000 as well as extra funds from several book deals.

On Sunday, Cruz suggested that a Trump presidency would be chaotic. At one point he referred to Rubio as a liar and a lightweight who doesn’t have temperament to be President. “Christie knows all that and indicated as much many times publicly”, Whitman said.

When asked about the endorsement, Cruz dodged on weighing in.

The Twitter hashtag has supporters from across the political spectrum – including conservatives – vowing to oppose Trump should he win the Republican nomination. He also took aim at Trump’s approach to interviews on Sean Hannity’s Fox News show in January: “He sits in his jammies in Trump Tower and phones in”.

“There have been multiple media reports about Donald’s business dealings with the mob, with the mafia”.

He said: “What we are dealing with here is a con artist”.