The phone calls and emails began coming in a few weeks ago to the Nebraska congressional delegation — all Republicans, and all potentially crucial to an expected fight over the very existence of the National Endowments for the Arts and the Humanities under President Trump.

The offices of Senators Ben Sasse and Deb Fischer and Representative Don Bacon heard from Erika Overturff, artistic director of Ballet Nebraska in Omaha.

Morrie Enders, who runs the Lincoln Community Playhouse, called the senators and Representative Jeff Fortenberry.

Andrew Norman, who promotes local music at a nonprofit called Hear Nebraska, put all five of the state’s federal lawmakers on speed dial.


“I have been calling them once a day,” he said.

With Trump administration officials now preparing deep cuts in domestic spending, including the possible elimination of the endowments, Republicans from politically red states like Nebraska could be decisive in saving federal funds for the arts and humanities. Endowment leaders in recent years have sought to support cultural programs and make allies in those conservative-leaning parts of the country. And now, Representative Fortenberry, for one, as a member of the House Appropriations Committee, will have outsize influence over the budgets for the endowments.

While Democrats have long supported the endowments, the coming budget proposals from President Trump will test the sort of Republicans who have been the rescuers and defenders of arts spending during the decadeslong efforts by conservatives to cut and even eliminate them.

“In the past, moderate Republicans have played a pivotal role in these fights,” said Suzanne Nossel, executive director of PEN America, the writers organization that is playing a central role in the lobbying. “Part of it is figuring out who is going to be the 2017 version of this.”

Among those friendly Republicans are Representative Leonard Lance of New Jersey, co-chairman of the House arts and humanities caucuses, who has been an enthusiastic supporter of continued funding and will be an important ambassador to other Republicans.

In an interview, Representative Lance said that, whatever President Trump’s budget blueprint proposes, “it’s the appropriations process that matters.”

“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.

“We have not heard,” Jessamyn Sarmiento, the N.E.A.’s director of public affairs, said in an interview. “We are not speculating on what may or may not be in the budget. We are going about our daily business.”

The message from the humanities endowment, which occupies floors in the same building, is similar. “We are doing our work,” said Theola DeBose, its communications director.

Efforts to cut cultural funding reach back to the days of Ronald Reagan. In the mid-1990s, Newt Gingrich used the Republican majorities in the House and Senate, and outrage among conservatives over some controversial art projects, to slash the two agencies’ budgets.

Today, supporters say, the agencies cost so little that killing them would be empty symbolism. What’s more, after the earlier conflicts, they emphasize that they have participation and support across the country, including Republican strongholds like Nebraska.

“We went through this before, in 1995 and 1996,” said Representative Jerrold Nadler, Democrat of New York. “If they succeed, it will hurt rural America. New York will still have art shows. It will be rural stations that come off the air.”

Powerful Republicans like the House speaker, Paul D. Ryan, of Wisconsin, and Senator Ted Cruz of Texas have in the past spoken out about eliminating the N.E.A. But some Republican support in the Senate is already evident. Susan Collins of Maine and Shelley Moore Capito of West Virginia were among 24 senators who signed a letter to President Trump, advocating for the arts, that was organized by Senator Kirsten Gillibrand of New York.

Senator Collins said in a statement that she continues “to believe there is bipartisan support for the arts and humanities, and I will work to encourage my colleagues on both sides of the aisle to maintain this important funding.”

Persuading other Republicans will be heavier lifting, Ms. Gillibrand acknowledged in an interview. But she said she intends to approach all her colleagues, perhaps starting with ones who are parents and may appreciate public television and the educational programs of endowments.

“It’s the kind of issue that affects all of them,” she said.

The first skirmishes over the N.E.A. and N.E.H. will be in the House Appropriations Subcommittee on Interior, Environment and Related Agencies.

As part of the budget process, this subcommittee drafts a bill that funds diverse agencies, including the National Park Service and the cultural endowments. Led by Representative Ken Calvert, Republican of California, the 11-member committee includes six other Republicans, who will be a key focus of advocates’ attention.

Some supporters are optimistic given the fact that the subcommittee, under Representative Calvert, voted to fund both agencies last year.

“Last year, that committee recommended a modest but significant increase,” said Heather Noonan of the League of American Orchestras. “There may be a distance between what the President proposes and what the Congress is willing to embrace.”

In Nebraska, where Mr. Trump took nearly 60 percent of the vote, officials from the state humanities and arts councils last month visited the office of Representative Bacon, a former Air Force brigadier general, and made sure to tell his staff about a high school program about world affairs and an art guild run by military veterans they were trying to help.

“It resonated,” said Suzanne Wise, executive director of the Nebraska Arts Council.

But it’s not clear exactly how the Nebraska delegation as a whole will come down. Molly O’Holleran, a member of the state board of education, said she was hopeful to win support from Senator Fischer. She has called and emailed the senator and got a letter back this week from the senator saying she, too, understood “the importance of ensuring access to the arts and humanities,” and would keep Ms. O’Holleran’s comments in mind.

“I am hoping,” Ms. O’Holleran said, “that our representatives are thinking how arts and humanities can build creativity and innovation, which makes America great.”