Demonstrators sit along Pennsylvania Avenue in front of the White House last year. The National Park Service is exploring whether it should recoup from protest organizers the cost of providing law enforcement and other support services for demonstrations. (Pablo Martinez Monsivais/AP)

President Trump’s pick to lead the National Park Service will face questions from senators this week about whether he believes that the agency should charge protesters for the costs of security and further limit where in Washington demonstrators can gather.

It’s a litmus test that could determine how divisive the nominee may become.

David Vela, superintendent at Grand Teton National Park, is scheduled to appear Thursday before the Senate Energy and Natural Resources Committee. Senators will have a chance to ask him about more than a dozen proposed Park Service rule changes.

Several committee members already have raised objections: In a letter sent last month to Interior Secretary Ryan Zinke, 16 senators wrote that they were “deeply concerned this rule will impede the public’s First Amendment rights to protest in and around our capitol.”

The Park Service in August proposed changes to how the agency facilitates protests in the District — including how many people may lawfully gather in parks without written permission and how much of the White House sidewalk protesters are allowed to occupy.

The suggestion that drew the most outrage was a query on whether the agency should consider charging organizers for the costs of large-scale demonstrations. The Park Service said limited resources have made facilitating such demonstrations difficult — particularly as they have grown in size and frequency.

Park Service officials haven’t estimated how much the agency spends each year to support protests and rallies, but spokesman Mike Litterst said that, on average, processing permits alone costs the Park Service about $700,000 in staff time. The average number of permitted protests in Washington has ballooned to 750 annually, Litterst said.

The Park Service has helped to coordinate hundreds of demonstrations this year, including the second Women’s March, the March for Our Lives and the Unite the Right white-nationalist demonstration, which drew thousands of counterprotesters and required intricate security plans that cost the D.C. government $2.6 million in policing and other expenses, according to a preliminary estimate.

Activists who want to host large demonstrations in Washington already are required to cover certain costs, including providing toilets, on-site emergency medics and cleanup services.

“While we recognize these budgetary concerns, imposing demonstration fees to cover NPS’ costs will undeniably burden the constitutionally protected right to peacefully assemble and engage in free speech,” the senators’ letter said. “ . . . Our fundamental rights cannot be stifled by a ‘pay to demonstrate’ fee.”

Four senators on the Energy and Natural Resources Committee signed the letter to Zinke. Three are Democrats — Tammy Duckworth (Ill.), Ron Wyden (Ore.) and Catherine Cortez Masto (Nev.) — and the fourth is Bernie Sanders (I-Vt.).

The American Civil Liberties Union said several Republican senators on the committee also have shown interest in the issue.

“Everyone with any kind of political opinion has things to protest — and they do,” said Art Spitzer, legal co-director of the ACLU of the District of Columbia. “On this committee alone, there are several on the Republican side who are consistently pretty attuned to the Constitution and, we hope, will be pretty concerned about the constitutional impact a rule like this would have.”

During a 60-day public comment period, more than 140,000 responses were submitted to the Park Service. Among them were lengthy takedowns of the proposal, including a 33-page missive from the ACLU and a warning from Del. Eleanor Holmes Norton (D-D.C.) indicating that should the Park Service proceed, it would face challenges from Norton, her “colleagues in Congress and, I believe,” she wrote, “the courts.”

With Vela heading toward a confirmation hearing before the Senate, the ACLU hopes to take the matter one step further by harnessing the public’s interest to push Vela to guarantee that, if appointed, he would reconsider the Park Service’s position.

“Our ask to senators is to not just have questions but demand that [Vela] commit to withdrawing this proposal,” said Chris Anders, a national lobbyist for the ACLU.

ACLU officials said a verbal guarantee from Vela could carry more weight than the public comments on the proposal. Though many of the comments appeared to be criticisms — tens of thousands contained words like “oppose,” “do not support” and “unconstitutional” — it wasn’t clear how heavily the feedback would be weighted.

“Public comment is not a vote,” Spitzer said. “There’s nothing that prevents [the Park Service] in the end from saying, ‘We received thousands of comments from people opposed who all largely think this would be unconstitutional, and we disagree.’ . . . And then they can ignore them and do what they want.”