Just days before final ballots are cast in the critical 2018 midterm races, Republicans are now faced with questions about President Donald Trump’s last-minute proclamation that he will move to end birthright citizenship.

A number of Republicans on the campaign trail have either distanced themselves from Trump on the issue, or expressed skepticism that the president has the authority to make such a change.

The issue came to the forefront after a clip of an interview Trump gave to “Axios on HBO” aired Tuesday, in which he said that he would soon sign an executive order to eliminate birthright citizenship and make it so that children born in the U.S. to non-citizens would not automatically become U.S. citizens.

The right is enshrined in the 14th Amendment, as many were quick to point out. The Constitution states that “all persons born or naturalized in the United States and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.”

But Trump told Axios that he believes he doesn’t need to amend the Constitution in order to curtail birthright citizenship. And, as MSNBC legal analyst Danny Cevallos wrote Tuesday, there has been some debate over whether the phrase “subject to the jurisdiction thereof” provides Trump with wiggle room.

One of the most forceful GOP condemnations on the trail of Trump’s birthright citizenship proposition came from Republican Senate candidate Bob Hugin, who is running in a surprisingly tight race with Democratic Sen. Bob Menendez in solidly blue New Jersey.

Hugin said in a tweet that Trump was “wrong” to try and end birthright citizenship.

Elsewhere, Republican Rep. Carlos Curbelo of Florida, who is running for re-election, told MSNBC’s Andrea Mitchell on Wednesday that the 14th Amendment is “clear” when it comes to the issue of birthright citizenship.

“This is a right that’s protected by the Constitution,” he said, adding that “this divisive rhetoric, this divide and conquer strategy that the president is employing and that more and more politicians employ by the year, is just deeply troubling.”

Other Republicans running for office, while offering support for Trump’s idea, expressed skepticism as to whether he could legally do it.

Republican Josh Hawley, running for Senate in Missouri against Democratic Sen. Claire McCaskill, told reporters in a Wednesday conference call that the 14th Amendment cannot be changed by executive order or statute, though he said the Supreme Court could decide to weigh in on the section of the amendment that Trump and other immigration hawks have highlighted.

Former Republican Rep. Ron DeSantis, who is running for governor in Florida and is a close ally of the president, told supporters at a Tuesday rally that he approves of Trump ending birthright citizenship. But, DeSantis said “there’s been a long list of [Supreme Court] decisions that I think you’d have to reckon with.”

House Speaker Paul Ryan, who is not running for re-election, offered much more choice words for the president, telling Kentucky talk radio station WVLK on Tuesday that Trump “obviously cannot” end birthright citizenship by executive order. The comments drew a rebuke from Trump on Twitter Wednesday.

Barry Bennett, a former Trump campaign adviser, told NBC News that Republicans on the trail should offer a simple answer when pressed about the president’s recent remarks.

“They should say our country’s immigration policies are in dire need of a complete rewrite,” he said.