Democratic pollster Anna Greenberg said Wednesday that the problem with the immigration debate is that not enough people are thinking about the issue in terms of policy.

"I think the challenge here is there's a difference between policy and attitudes," Greenberg, a partner at Greenberg Quinlan Rosener, told Hill.TV's Jamal Simmons on "What America's Thinking."

"The problem is is that for many people, they think of immigration not in terms of policy, but around race and xenophobia," she said.

"In a particular way, this president has used it as a cudgel to activate, I think, some of our worst tendencies in this country," she added. "Until we can sort of tamp down that aspect of it, it's very hard to get to a policy solution in particular for Republicans who worry about people primarying them."

President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE used the issue of border security to rally Republican voters to the polls during the November midterm elections. In particular, he focused on what he characterized as a national security threat posed by Central American migrants making their way to the U.S. border with Mexico.

The president on Tuesday threatened a partial government shutdown if Congress does not approve the amount of funding he's seeking for a U.S.-Mexico border wall.

— Julia Manchester