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Donald Trump and Hillary Clinton continued their primary dominance Tuesday night, scoring convincing wins in their respective Arizona primaries.

Trump's win, called by the Associated Press, will deliver to him all the state’s 58 delegates. Arizona was the largest remaining wier-take-all GOP contest.

On the Democratic side, 75 delegates were at stake and will be awarded proportionally.

Meanwhile, a frenzy of activity and tuout snarled polling places Tuesday across the Weste contests, leading to waits of over two hours at some locations in Arizona.

In Utah, the state Democratic Party's website crashed due to high traffic. And Democratic leaders kept locations open longer than plaed in Idaho, which was holding Democratic caucuses.

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Across the three states, Clinton and Trump looked to build on their delegate leads. Delegates also were up for grabs in Utah’s GOP caucuses, with results not expected until early Wednesday moing.

The contests were being held in the shadow of the latest deadly terror attack, in Brussels, a tragedy that brought national security and foreign policy hurtling back to the forefront of the campaign trail debate.

The Weste state contests, for Republicans in particular, also mark one of the last chances to set the tone of the race before a lull in the primary calendar. Democrats have another round of contests this weekend, but Republicans will compete in only one state over the course of the next four weeks.

Amid efforts by his rivals to force an “open” convention in July, Trump has voiced confidence in recent days that he can clinch the GOP nomination by wiing 1,237 delegates before then. Both Trump and Democratic front-ruer Clinton have been eager to tu to a general election battle, each expecting to face the other in November.

But Trump likely will have to wait at least until late April, when the next round of major contests is held, to have a chance at driving his remaining rivals out of the race.

On the Democratic side, Beie Sanders is clinging to hope that as the race tus from Clinton’s Southe stronghold to Weste and other states, he can start to make up his gaping delegate deficit. His road to victory remains incredibly narrow.

The underdogs’ goal on the Republican side may be more attainable: Win just enough delegates to hold Trump under the requisite 1,237 delegates and trigger a contested convention in Cleveland.

Going into Tuesday’s contests, Trump led Texas Sen. Ted Cruz in the delegate count 681-425. Ohio Gov. John Kasich trailed with 143.

From the start, Arizona's primary seemed custom-made for a Trump victory. The state has long dealt with illegal immigration problems, and the Republican front-ruer's central campaign promise is to build a wall across the entire southe U.S. border. Trump also enjoyed the backing of former Arizona GOP Gov. Jan Brewer and Maricopa County Sheriff Joe Arpaio, two of the most outspoken voices on illegal immigration.

Yet Cruz appears poised to do well in Utah, which offers 40 delegates.

Mormons are a large voting bloc there, and Trump lost to Cruz in Mormon-heavy Idaho earlier this month. Fellow Mormon and outspoken Trump critic Mitt Romney, the 2012 GOP presidential nominee, remains influential in Utah and has tried to get out the vote for Cruz in recent days. If Cruz can not only win but gaer more than 50 percent of the vote, he could also pocket all 40 delegates.

Joe Desilets, a Republican strategist and managing partner at the firm 21st&Main, said doing so would be a “blow to Trump” as he tries to clinch the nomination.

As voters went to the polls Tuesday, national security once again was front and center, in the aftermath of the Brussels terror bombings for which the Islamic State has taken responsibility.

Earlier, Trump called for an end to the U.S. Visa Waiver Program and told Fox News, “I’ve been talking about this for a long time.”

Cruz went more directly at President Obama and his immigration policies, including his plan to allow tens of thousands of Syrian refugees into the United States.

“The time for the president’s political correctness has passed,” Cruz said. “We absolutely have to revisit our immigration policy across the board to prevent Islamic terrorists from coming in.”

On the Democratic side, Clinton and Sanders are competing for 33 delegates in Utah and 23 in Idaho.

Sanders desperately is looking for a win after getting swept in five March 15 contests. Going into Tuesday’s contests, he trailed in delegates 1,630-870, with 2,383 needed to win the party nomination.

Though Clinton led in Arizona polls, Sanders invested a lot of time in Arizona including a campaign stop this weekend to the U.S.-Mexico border. And he was the only 2016 presidential candidate to skip speaking Monday at the American Israel Public Affairs Committee conference in Washington to stay on the campaign trail.

The Associated Press contributed to this report.