Donald Trump’s sweep across five eastern states in primary contests Tuesday night raises immediate questions about the newly formed alliance between Ted Cruz and John Kasich and whether it can stop the Republican frontrunner – even as the two underdog candidates vowed to keep fighting on.

Trump won victories in Connecticut, Pennsylvania, Rhode Island, Maryland and Delaware, increasing his already significant delegate lead over his competitors.

While Cruz holds more delegates than Kasich, the Ohio governor beat Cruz in Delaware, Rhode Island and Connecticut. Both campaigns pledged to keep going, with Kasich’s campaign tweeting that he “will continue making his supporters proud.”

Cruz also struck an optimistic tone, telling supporters “tonight this campaign moves back to more favorable terrain.”

That more favorable terrain includes states such as Indiana, where Cruz is hoping for a strong showing, and New Mexico and Oregon, where Kasich is hoping to deny Trump victory.

The Cruz and Kasich campaigns announced Sunday that the Ohio governor would shift his campaign resources to give Cruz a clear run in Indiana, which votes on May 3. In return, the Texas senator's campaign would allow Kasich a clear path in Oregon — which holds its primary on May 17 — and New Mexico, which votes on June 7.

But the results Tuesday raise the question of whether the Hail Mary play even has a prayer. With Trump sweeping the field, it is unclear if Cruz and Kasich have enough clout to be able to deny Trump the nomination.

Neither Cruz nor Kasich have a mathematical path to the 1,237 delegates needed to win the nomination before the July convention, although Trump’s path to outright victory is also narrow. But the anti-Trump forces need to pick up wins in order to shut down the billionaire.

Trump’s sweep puts him one more step out of Cruz and Kasich’s grasp. Despite placing second in a number of states, primary rules mean Kasich will walk away with only a handful more delegates, while giving Trump the lion’s share. With 623 delegates remaining, Trump now has 950, Cruz has 559 and Kasich has 153.

The wins help Trump not only in terms of delegates, but also give the billionaire bragging rights and the ability to rhetorically sidelinehis rivals. On Tuesday he said about the primary race: “As far as I’m concerned it’s over.”

The Cruz-Kasich strategy had already been facing difficulties. Shortly after the plan was announced, Kasich undercut the strategy Monday, saying “I’ve never told [supporters] not to vote for me. They ought to vote for me.” He sought to downplay the strategy as well, describing it as “not a big deal.”

Kasich’s struggling campaign was dealt another blow when it was revealed Monday that Kasich was not featured in an Oregon voters’ guide after the campaign missed the deadline to submit information for the pamphlet.

Even in states like Indiana, where Cruz is investing his resources, he still trails significantly behind Trump. The latest Fox News poll gave Trump an eight point lead over Cruz. Trump collected 41 percent, while Cruz had 33. Kasich was a distant third with 16 percent.