“If it were to happen that it is not in the budget document, I would fight in the appropriation process to continue the funding,” he added.

Since federal agencies cannot lobby, the fight to save the N.E.A., the equally endangered National Endowment for the Humanities, and the Corporation for Public Broadcasting falls to advocacy groups like PEN, and the American Alliance of Museums, Americans for the Arts, and the Federation of State Humanities Councils. They plan to flood congressional offices here with hundreds of members in the next few weeks.

“This would be crunch season for us even in a normal year,” said Ben Kershaw, director of government relations for the American Alliance of Museums, whose members are in Washington this week, “but this year we have kind of a lot going on.”

Little of the turmoil is evident in the hallways of the large modern building, south of the National Mall, that is home to the N.E.A. The agency’s chairwoman, Jane Chu, traveled to Florida last week to meet with a grant recipient, a routine event, and declined to discuss the pressures likely facing her agency, whose budget of $148 million is less than what was allotted two decades ago before big cuts. (As for the N.E.H., it receives about $150 million annually.)

Two transition team members from the Trump administration are working alongside the N.E.A.’s 156-member staff. But even as the agency’s supporters plan visits to Congress, the idea that it could be on a draft hit list of programs to be eliminated is still unconfirmed.