If they don’t challenge Trump on the wall and immigration, though, Democrats will likely face the wrath of their base, which is livid after high-profile immigration raids and new policies like unlimited detention of migrants or deporting sick immigrants.

“There is a greater and greater sense in the Democratic Party that any support of the administration’s policies is giving cover to moral wrongdoing,” said Rep. Ro Khanna (D-Calif.), adding that Democrats should insist on providing zero new money for the wall, even as the White House has found ways to circumvent Congress to secure billions for the wall by shifting funds away from military construction projects.

But a funding fight over border security also risks exposing divides within the Democratic party — reigniting an emotional debate that nearly tore the caucus apart earlier this summer. And those tensions could complicate Democrats’ efforts to complete their packed fall agenda.