So, does Collins support Trump's candidacy? Yes, a campaign spokesman later said.
Broun said backing Trump is a must.
"Absolutely," he said. "We’ve go to unite the Republican Party because our country hangs in the balance. If we don’t come together and support Mr. Trump, who is obviously the people’s choice as a candidate, it’s absolutely dangerous that somebody like Hillary Clinton might be elected."
But Broun also faced questions about ethics charges swirling around his former time in the U.S. House. Federal prosecutors secured an indictment last month to charge Broun's former chief of staff, It's unclear if the Justice Department's corruption investigation will stop there or engulf the former four-term congressman.
The central question is how much Broun knew and whether he was involved in discussions to cover up the role Republican consultant Brett O'Donnell had with his office and campaigns.
"We’ve answered this at great length," Broun said during Friday's debate. "If my chief of staff is indeed guilty of anything it’s because he willfully and directly disobeyed orders I gave him."
Broun said "absolutely not," when asked if he should be held responsible for any criminal activity in his office.
On immigration, the four challengers also said Trump was correct to call for a temporary ban on Muslim immigrants to the United States.
"Donald apparently was not politically correct but he was very right in his common sense approach that you have to stop the danger," Fontaine said. "We need to quit talking about theory and let’s live in the real world."
Scupin and Fitzpatrick agreed, and blasted Collins for voting a massive spending bill last year that funded the relocation of thousands of Syrian refugees to the United States.
"Nearly everything the president asked for on immigration was approved in this bill," Scupin said. "He is not voting for the people."
Collins, the incumbent, said he has kept the promises he made four years ago.
"We’ve had a lot of fights, but at the core it was always what was best for our district," he said.