The March for Life rally may just have kicked off, but organizers are already planning next year's event.

Protests of this magnitude can take months to plan, and spaces around Capitol Hill fill up quickly.

The National Park Service, which handles permits for the National Mall, grants more than 3,000 applications for special events each year. Of those about 300 are political demonstrations.

On any given day, there may be eight other events happening just on the park grounds. Those activities vary from arts and literary festivals to aircraft displays by defense contractors.

The good news for organizers is that political demonstrations get priority.

"First amendment activities are legitimate protests either in support of or against a government policy," said Bill Line, spokesman for the small office that handles permit applications. "That can range from any issue under the sun."

Among those applicants, it's first come, first serve.

"We treat everybody the same way. We are content neutral on the message," he said.

Every event that is expected to draw more than 25 people requires a permit. The permit form can be filed one calendar year in advance.

"The point is that one singular office knows what other events, marches, and demonstrations are taking place on the National Mall on any given day," he said.

Line offered three tips to organizers:

* Get a map. The areas around the Capitol are under different jurisdictions. To march from the White House to the National Mall, for example, only the sidewalks can be used if organizers filed just with Line's office.

"We issue permits for the sidewalks of Pennsylvania Avenue, not the asphalt," he said. The asphalt belongs to city police.

Take the anti-abortion rally: Marchers plan to head down Constitution Avenue towards the Supreme Court.

For that portion of the protest, they have a permit from the D.C. police department. Were they to step onto Capitol Hill, they would need a permit from the Capitol Police as well.

* Be detailed. Organizers need to know where on the Mall they want to protest, how many people may come, what equipment and props will be used, and whether they will need police protection.

"The group has to describe in pretty good detail what it is that they're planning to do," Line said. He noted that very few protests get rejected, and that his office works with groups to firm up details.

* Plan ahead. The permit office holds multiple meetings with event organizers leading up to the event. And as political battles heat up in Washington, so does the demand for permits.

When asked when the staff is busiest, Line said, "it's literally determined by what's going on in the political world."

Ambreen Ali writes for Congress.org.