On NBC's "Today" show, Trump said he would be "fine" with waterboarding Salah Abdeslam, an organizer of the Paris attacks recently captured in Brussels. "Frankly the waterboarding, if it was up to me, and if we changed the laws or have the laws, waterboarding would be fine. If they could expand the laws, I would do a lot more than waterboarding." Trump also said if the Brussels attacks happened in the U.S. he would "shut down" the borders.

"I will tell you, I've been talking about this a long time, and look at Brussels," Trump said on Fox News. "Brussels was a beautiful city, a beautiful place with zero crime. And now it's a disaster city. It's a total disaster, and we have to be very careful in the United States, we have to be very careful and very vigilant as to who we allow in this country."

Trump , who has based his campaign on cracking down on immigration including a proposed ban on all Muslims entering the U.S., immediately seized on the Brussels attacks.

As Republican voters head to the polls Tuesday in Arizona and Utah, the world's attention turned to Brussels where terrorists killed at least 31 with bombs at the city's main airport and on a subway train. The strikes come four months after attacks in Paris, claimed by ISIS, killed 130 people.

The attacks in Brussels will once again drive terrorism to the top of the presidential campaign agenda and could give a boost to Donald Trump and his fiery anti-immigrant rhetoric.

Sen. Ted Cruz (R-Texas), Trump's main rival for the GOP nomination, also reacted strongly to the Brussels attack but stopped short of Trump's rhetoric, focusing instead on criticizing President Barack Obama. "Radical Islam is at war with us. For over seven years we have had a president who refuses to acknowledge this reality," Cruz said in a statement on Facebook. "And the truth is, we can never hope to defeat this evil so long as we refuse to even name it. That ends on Jan. 20, 2017, when I am sworn in as president."

The Brussels attacks will not fundamentally alter the nature of the Republican presidential campaign but it may further motivate Trump's most fervent supporters who strongly back his call to block Muslim immigration, reject Syrian refugees and build a giant wall with Mexico somehow paid for by the Mexican government.

In Tuesday's primaries, Trump is likely to score a win in Arizona, where the victor gets all of the state's 58 delegates. But Cruz is expected to beat Trump easily in Utah, whose large Mormon population is deeply hostile to Trump and his rhetoric. Such a split decision will keep alive GOP establishment hopes to stop Trump from getting the 1,237 delegates he needs to secure the nomination before the party's convention in July.

The next battleground will come in Wisconsin, which votes April 5 and awards most of its 42 delegates to the statewide winner. Trump is deeply unpopular in reliably Republican counties outside Milwaukee but draws strong support — as he often does — among struggling white voters in more rural areas of the state. Wisconsin may come down to the level of turnout in these blue-collar Trump strongholds versus the more establishment-friendly areas around Milwaukee. And Trump's angry reaction to the Brussels bombing could drive numbers up among his staunchest supporters. Cruz, once again, will see some of the anti-Trump vote siphoned off by moderate Ohio Gov. John Kasich.

From Wisconsin, the GOP race will turn to the Northeast with a primary in Trump's home state of New York on April 19 that he is expected to win by a large margin. A week later, voters go to the polls in Connecticut, Delaware, Maryland, Pennsylvania and Rhode Island. If Trump sweeps Wisconsin and New York and most of the April 26 states, he will be on track to win the delegates he needs to avoided a contested convention.

The Brussels attacks on Tuesday will also distract from a rambling and bizarre interview Trump gave to The Washington Post editorial board on Monday in which he rolled out a foreign policy advisory team that baffled many in the party. Asked if he would target ISIS with a tactical nuclear weapon, Trump responded that reporters and editorial writers at the meeting were all very good looking.

Now few will be talking about those gaffes and instead will focus on the need to be ever more vigilant against terrorist attacks both in the heart of Europe and potentially on American soil. That's Trump's most comfortable ground.