Sen. Joe Manchin Joseph (Joe) ManchinThe Hill's Morning Report - Sponsored by Facebook - Trump, GOP allies prepare for SCOTUS nomination this week Trump meets with potential Supreme Court pick Amy Coney Barrett at White House Names to watch as Trump picks Ginsburg replacement on Supreme Court MORE (D-W.Va.) said Thursday that the concept of granting birthright citizenship is "worthy of looking at," but was adamant that President Trump Donald John TrumpOmar fires back at Trump over rally remarks: 'This is my country' Pelosi: Trump hurrying to fill SCOTUS seat so he can repeal ObamaCare Trump mocks Biden appearance, mask use ahead of first debate MORE cannot change it via executive order as he has suggested.

"I think it’s worthy of looking at it. I think the president needs to say what he intends to do," Manchin said during a West Virginia Senate debate.

"I think there’s a lot can be done, and a lot can be controlled, but he cannot do it by an executive order," the senator added, arguing the president can't unilaterally change the Constitution.

ADVERTISEMENT

Manchin's opponent, Republican Patrick Morrisey, said Trump is "right to look at the birthright lottery," but added he would want to see the president's executive order to ensure it's being handled the right way.

Manchin, who is up for reelection in a state Trump won easily in 2016, joined Sen. Joe Donnelly Joseph (Joe) Simon DonnellyTrump meets with potential Supreme Court pick Amy Coney Barrett at White House Names to watch as Trump picks Ginsburg replacement on Supreme Court Momentum growing among Republicans for Supreme Court vote before Election Day MORE (Ind.), another vulnerable Democrat, in appearing open to the idea of ending birthright citizenship.

In an interview with Axios published Tuesday, Trump vowed to end citizenship for children of nonlegal residents born in the U.S., a change he proposed during the 2016 campaign.

He did not indicate when he would sign such an order, but the concept is one of many he has floated in the closing days of the campaign regarding immigration.

A number of lawmakers, including Speaker Paul Ryan Paul Davis RyanKenosha will be a good bellwether in 2020 At indoor rally, Pence says election runs through Wisconsin Juan Williams: Breaking down the debates MORE (R-Wis.), Sen. Jeff Flake Jeffrey (Jeff) Lane FlakeJeff Flake: Republicans 'should hold the same position' on SCOTUS vacancy as 2016 Republican former Michigan governor says he's voting for Biden Maybe they just don't like cowboys: The president is successful, some just don't like his style MORE (R-Ariz.) and Chuck Grassley Charles (Chuck) Ernest GrassleyCollins says she will vote 'no' on Supreme Court nominee before election The Hill's Morning Report - Sponsored by Facebook - Trump, GOP allies prepare for SCOTUS nomination this week Gardner signals support for taking up Supreme Court nominee this year MORE (R-Iowa) promptly refuted Trump's assertion that he can end birthright citizenship via executive order since it is enshrined under the 14th Amendment.

"Well, you obviously cannot do that. You cannot end birthright citizenship with an executive order," Ryan told WVLK radio in Lexington, Ky.

Trump responded to the criticism on Wednesday, saying birthright citizenship would be ended "one way or another" and attacking Ryan.