Republican Donald Trump amped up attacks against rivals Ted Cruz and John Kasich on Monday after they announced an agreement to try to block the New York billionaire from winning the party's U.S. presidential nomination.
Trump is expected to sweep the five states holding primary elections on Tuesday, prompting Cruz and Kasich to announce their unusual tactic of agreeing not to compete against each other in Indiana, New Mexico and Oregon.
In a sign that Cruz has no intention of backing out of the race before the July convention in Cleveland, his campaign manger Jeff Roe posted on Twitter on Monday that they had narrowed the search for a vice presidential running mate to a "short list" and were vetting potential candidates. Traditionally, candidates wait until they have secured the nomination to select a running mate.
Trump denounced the move by his opponents to band together as disgusting and compared it to illegal collusion in stock trading.
"It shows how weak they are. It shows how pathetic they are," Trump told a crowd in Warwick, Rhode Island.
He revived attacks against Cruz that none of his fellow senators like him and mocked Kasich for the way he ate breakfast during a televised news conference on Monday morning.
Cruz, a U.S. senator from Texas and Trump's closest challenger, said the deal with Kasich was aimed at preventing a Trump nomination that he argues would assure victory for Democrat Hillary Clinton in the Nov. 8 presidential election.
The Cruz-Kasich deal was announced on Sunday before a handful of primary elections in several mid-Atlantic states on Tuesday. It is the latest unusual move in what has been a topsy-turvy Republican presidential race in which early favorites fell to political outsider Trump, whose unexpected rise has left establishment Republicans grappling with a new order.
"It's another exciting day in Republican politics," Republican National Committee spokesman Sean Spicer said on MSNBC.
To derail Trump, the Cruz and Kasich campaigns agreed to concentrate their efforts and resources in state contests where each has a better shot. Cruz will focus on Indiana's May 3 primary without competition from Kasich, while Cruz will stand aside in favor of Kasich in Oregon's May 17 primary and New Mexico's June 7 vote.
Trump, who often talks about being the consummate dealmaker, accused his rivals of "a horrible act of desperation" by colluding in Oregon, New Mexico and Indiana.
"You know, if you collude in business or if you collude in the stock market, they put you in jail," Trump said in Warwick. "But in politics - because it's a rigged system, because it's a corrupt enterprise - in politics, you're allowed to collude."
"SHAKE THINGS UP"
The move is unique in modern presidential politics and signaled panic after Trump's sweeping victory in the New York primary last week, said Larry Sabato, director of the University of Virginia's Center for Politics.
"They know he's going to have a great night tomorrow," Sabato said. "If things are not shaken up, Trump's going to be the nominee. They have to do something big to shake things up. They're hoping that this is it. Maybe it is, maybe it isn't."
Cruz said it was Trump who was desperate because he knows he has a difficult path to the 1,237 delegates needed to secure the party's nomination at the Republican National Convention in July.
"I don't doubt that Donald Trump is going to scream and yell and curse and insult and probably cry and whine some as well," Cruz said in Indiana. "That has been Donald's pattern."
Cruz and Kasich, who is Ohio's governor, hope their efforts will weaken Trump in Oregon, Indiana and New Mexico and keep him from securing the delegates he needs to claim the nomination before the Republican National Convention in Cleveland in July.
"This is going to go to an open convention," Kasich told supporters in Rockville, Maryland, on Monday.
Earlier in Philadelphia, Kasich tried to play down the alliance with Cruz as simply a way for him to save money by not campaigning in certain areas. He said he was not asking supporters in those places not to vote for him.
"So what? What's the big deal?" Kasich said. "I'm not over there campaigning and spending resources. We have limited resources."
Trump has dominated the nominating contests so far but still faces a tough path to earn the delegates needed to lock up the nomination before the convention. A candidate who wins a state contest sometimes still must win over delegates who often are allocated at separate events. Republicans will pick their delegates in at least four states this weekend, including Alaska, Arkansas, Arizona and Virginia.
Trump said the Cruz-Kasich deal bolstered his contention that the Republican system for choosing delegates is rigged. Party officials have said the rules have long been known.
If no candidate has enough delegate support on the first vote at the national convention, many delegates can switch to another candidate on subsequent ballots.
The move by Kasich and Cruz could be motivated by simple math - it is virtually impossible for either to get enough delegates to win the nomination.
"A lot of observers were urging them to do this weeks or months ago, right after Rubio dropped out," Sabato said.