House Speaker Nancy Pelosi (D-CA) warned Republicans on Thursday that they should worry about the “threshold that they are crossing” by supporting President Donald Trump’s expected declaration of a national emergency at the border because it could open the door to future Democrats in the White House declaring a national emergency on issues like gun control.

With Trump expected to sign a spending bill to keep the government open and declare a national emergency to get more funding for his border wall, Pelosi said Republicans “have some unease about it no matter what they say” because “if the president can declare an emergency on something that he has created as an emergency, an illusion that he wants to convey, just think of what a president with much different values can present to the American people.”

Pelosi said she is not advocating presidents doing an “end run around Congress,” but warned that a “Democratic president can” declare national emergencies as well on issues like gun control, and “the precedent that the president is setting is something that should be met with great unease and dismay by the Republicans.”

“You want to talk about a national emergency? Let’s talk about today—the one-year anniversary of another manifestation of the epidemic of gun violence in America. That’s a national emergency,” Pelosi said, in reference to the one-year anniversary of the Parkland shooting. “Why don’t you declare that a national emergency, Mr. President? I wish you would.”

She emphasized that Republicans should “have some dismay about the door that they are opening, the threshold that they are crossing” with Trump’s expected declaration of a national emergency at the border.