Americans are almost evenly split over whether Congress should heed President Trump Donald John TrumpSteele Dossier sub-source was subject of FBI counterintelligence probe Pelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' Trump 'no longer angry' at Romney because of Supreme Court stance MORE's call to fully fund a border wall between the United States and Mexico, a new Hill.TV American Barometer survey found.

The poll, conducted by the HarrisX polling company, found that 49 percent of voters backed the idea of funding a border wall in order to avoid a partial government shutdown, while 51 percent disagreed.

During his 2016 campaign, Trump made immigration his signature issue, and as president he has repeatedly demanded that Congress appropriate money for the entire border wall project instead of allocating annual amounts.

On Thursday, Trump reiterated a threat to partially shut down the federal government if Congress does not completely fund the barrier.

"Could there be a shutdown? There certainly could, and it will be about border security, of which the wall is a part," Trump said during a brief Thanksgiving press conference at his Mar-a-Lago resort in Florida.

Trump's proposed border wall is not popular among voters, but bundling it with a mandatory spending bill will likely increase public support for the barrier, said Ruy Teixeira, a senior fellow at the left-leaning Center for American Progress, during Monday's broadcast of Hill.TV's "What America's Thinking."

"People are very inclined to say, 'Well, shoot, we don't want a shutdown, so maybe I'm OK with that.' But if you look at other data about whether people favor the wall or not, it's like 2-to-1 against," he said. "So I don't think it's very likely the Democrats are going to cave on this one."

An April survey commissioned by The Associated Press found that 58 percent of U.S. adults opposed a border wall, while 28 percent supported it. A March survey conducted for CBS News found that 60 percent of adults surveyed were against the proposal, while 38 percent favored it.

"Pollsters have been asking questions about the wall ever since Trump mentioned it the first time and you very rarely see more than 40 percent support for a wall," Karlyn Bowman, a senior fellow at the right-leaning American Enterprise Institute told Joe Concha, host of "What America's Thinking."

Last year, Trump and Democrats almost reached a deal to fully fund the wall in exchange for granting permanent legal status to recipients of the Deferred Action for Childhood Arrivals program that was enacted by former President Obama.

The American Barometer survey was conducted Nov 24-25 among 1,000 registered voters. The sampling margin of error is plus or minus 3.1 percentage points.

—Matthew Sheffield