WASHINGTON (AP) — Republican Donald Trump and Democrat Hillary Clinton fought to boost their delegate leads over party challengers for the presidential nomination Tuesday in primary election voting across three Western states as the world grappled with a new wave of bloody attacks in Europe.
Arizona and Utah feature contests for both parties, while Idaho Democrats hold presidential caucuses, all of which will determine if Democrat Bernie Sanders and Republicans Ted Cruz and John Kasich can blunt the growing sense of inevitability around both party front-runners.
But the nominating contests were largely an afterthought for much of the day as the leading White House hopefuls clashed over how to stop the spread of the Islamic State group. The organization claimed responsibility for a series of attacks in Brussels that left at least 34 dead and dozens more wounded.
Even before Tuesday's violence, foreign policy had emerged as a central theme ahead of the Western elections with candidates in both parties courting pro-Israel activists on Monday.
On Tuesday, Cruz said that it was time for law enforcement to "patrol and secure Muslim neighborhoods before they become radicalized," without providing more details.
The ultraconservative Texas senator, who is running behind Trump in the Republican contest, made the comment in a statement his campaign released following the bombings in Brussels.
In separate interviews on CNN, Trump supported Cruz's proposal for increased surveillance in Muslim neighborhoods in the U.S., while Kasich opposed it.
Clinton as well as Trump's Republican rivals questioned whether the billionaire businessman has the temperament and readiness to serve as commander in chief, and condemned the Republican front-runner's calls to diminish U.S. involvement with NATO.
"This is a time for us to reaffirm our solidarity with our European friends and allies, individually and through NATO," Clinton declared on NBC's "Today," insisting that the U.S. must intensify efforts to prevent terrorism in conjunction with its allies. "We've got to be absolutely strong and smart and steady in how we respond."
Cruz seized on Trump's foreign policy inexperience while declaring that the U.S. is at war with the Islamic State group.
"He doesn't have the minimal knowledge one would expect from a staffer at the State Department, much less from the commander in chief," the Texas senator told reporters. "The stakes are too high for learning on the job."
Trump vowed to defeat the Islamic State, and he renewed his proposal for temporarily barring Muslims from entering the country in addition to refusing entry to Syrian refugees fleeing their war-torn nation.
"We're having a problem with Muslims coming into the country," Trump said on CNN. "The reason I'm leading on the Republican side by a lot ... is that I'm very, very strong on borders."
Trump's brash tone has turned off some Republican voters in heavily Mormon Utah, where preference polls suggest that Cruz has a chance to claim more than 50 percent of the caucus vote — and with it, all of Utah's 40 delegates. If Cruz fails to exceed 50 percent, the delegates would be awarded proportionally based on each candidate's vote total.
Kasich hopes to play spoiler in Utah, a state that prizes civility and religion. A week ago, the Ohio governor claimed a victory in his home state, his first and only win of the primary season. But Mitt Romney, a Mormon and the Republicans' 2012 presidential nominee, is telling his fellow Utah voters in a recorded phone message that Cruz "is the only Republican candidate who can defeat Donald Trump."
Trump appears to be in a stronger position in Arizona, which will award all of its 58 delegates to whichever candidate wins the most votes.
Anti-Trump Republicans are running out of time to prevent the billionaire businessman from securing the 1,237 delegates needed to claim the nomination. In primary voting and caucuses so far, Trump has 680 delegates, Cruz has 424 and Kasich has 143.
With more than half of all delegates already awarded during the first seven weeks of primary voting, Trump's challengers' best, and perhaps only, hope lies with denying him a delegate majority and forcing a contested national convention in July.
"This is going to the convention," Kasich said on CNN.
On the Democratic side, Clinton's advantage is even greater.
The former secretary of state is coming off last week's five-state sweep of Sanders, who remains popular among his party's most liberal voters but needs to improve his performance if he expects to stay relevant. The Vermont senator, now trailing Clinton by more than 300 pledged delegates, has targeted Tuesday's races as the start of a comeback tour.
The former first lady has 1,163 delegates to Sanders' 844, based on primaries and caucuses. It takes 2,383 delegates to win the nomination.