“President Obama and Hillary Clinton’s idea that we should bring tens of thousands of Syrian Muslim refugees to America — it is nothing less than lunacy,” Sen. Ted Cruz (R-Tex.) said Saturday in an interview on Fox News Channel. He added that only Christian refugees should be allowed to come to this country.

The attacks in Paris also raised a question for Republican voters: Will they continue to be drawn to the bellicose rhetoric most exemplified by front-running political outsider Donald Trump, or turn instead toward the experience of some of the current and former senators and governors in the race?

“Foreign policy is a gateway issue, and this is the moment in which the gate’s got to be hit by all the candidates,” said Kori Schake, a foreign policy expert at Stanford University’s conservative Hoover Institution. “It is a commander-in-chief test.”