The Texas senator and Ohio governor roiled the Republican presidential primary late Sunday with a coordinated effort to deny Donald Trump the nomination by dividing upcoming contests. Cruz will focus on Indiana, the campaign said, while Kasich would devote his efforts to Oregon and New Mexico.

But the competition between the two contenders was alive on the campaign trail Monday.

Cruz hailed Kasich's decision to "pull out of Indiana to give us a head-to-head contest with Donald Trump."

Kasich said the arrangement wasn't meant to discourage voters in Indiana, which holds its increasingly critical primary May 3, from supporting him.

"I've never told them not to vote for me," he said. "They ought to vote for me. But I'm not over there campaigning and spending resources."

'Collusion'

Trump, meanwhile, blasted the entire arrangement as "pathetic" and emblematic of the corrupt political system he's trying to disrupt.

"If you collude in business ... they put you in jail. But in politics ... you're allowed to collude," he said.

"It shows that they are just getting killed," Trump said, mocking Kasich's "1 for 41" showing in the primary race and saying Cruz was cracking under pressure.

"Actually I was happy, because it shows how weak they are, it shows how pathetic they are," Trump said.

The deal is a sign of the increasing odds facing GOP forces trying to stop Trump short of the 1,237 delegates he needs to clinch the nomination, following his huge win in New York last week and expected sweep of a string of northeastern primaries Tuesday. Should Trump win Indiana, which is effectively a winner-take-all race, it would be tough for Cruz and Kasich to stop him collecting the delegate haul needed to win a first convention vote in Cleveland in July.

'Crossroads'

Cruz on Monday said the Indiana primary on May 3 represented a "crossroads" in the Republican race and for the entire nation.

Kasich made a similar point, but the contentious nature of his exchanges with reporters Monday in Philadelphia underscored the fact that the deal with Cruz was an uneasy marriage of convenience rather than a natural alliance between their campaigns.

"What's the big deal?" Kasich asked reporters who peppered him with questions about decision to cede Indiana to Cruz.

Kasich's chief strategist tweeted that voters "get it" -- implying that they'll make the right decision on how to vote in next week's primary.

"We're not telling voters who to vote for in IN, only where we are going to spend resources to ultimately defeat Hillary. They get it," John Weaver tweeted.

We're not telling voters who to vote for in IN, only where we are going to spend resources to ultimately defeat Hillary. They get it. — John Weaver (@JWGOP) April 25, 2016

But Trump refuted the claim by Cruz and Kasich that he would be routed by Clinton in November, presuming she is the Democratic nominee.

"I will beat Hillary Clinton," Trump said. "Lyin Ted Cruz will lose so badly to Crooked Hillary it will be one of the great defeats ever, and Kasich will also as soon as they put up the negative ads."

The Kasich-Cruz deal is the first formal attempt in the long Republican primary to coalesce opposition to Trump, who has benefited from the divided field to romp though primary season despite sometimes failing to capture a majority of votes in primary races.

But it may have emerged too late to stop Trump's march toward the nomination as he is the only remaining candidate with a chance to secure the party's presidential ticket by conventional means.

Still, Kasich's decision not to compete with Cruz in Indiana could make the state race much closer. Added together, the combined total of voters backing Cruz and Kasich in Indiana is greater than Trump's 41% in a Fox News poll published last week.

There is no guarantee that all of Kasich's voters will decide to line up behind Cruz since the Texas senator's conservative ideology is far more hardline than the Ohio governor's philosophy.

"This is something that Washington doesn't understand about politics -- nobody's supporters 100% go to anybody," said Barry Bennett, a senior Trump advisor told CNN's "At This Hour."

"This is really pathetic. This is crazy."