President Donald Trump reached a deal with House Minority Leader Nancy Pelosi (D-CA) and Senate Majority Leader Chuck Schumer (D-NY) to raise the debt limit, fund Hurricane Harvey relief, and keep the government open until December.

The deal is a warning to Republicans — primarily to the party establishment, which has fought Trump at every turn, but also to conservative Republicans, who have long worried about Trump shifting leftwards.

It is no secret that Trump is frustrated with the party establishment, and particularly with congressional leaders, notably Senate Majority Leader Mitch McConnell, who failed to whip his caucus into delivering the votes to repeal and replace Obamacare.

Conservatives were blamed for stalling the American Health Care Act in the House. But it was the moderates who tanked the Better Care Reconciliation Act in the Senate, and the last-ditch “skinny repeal.”

Trump has long warned that he would work with Democrats, if necessary, to fulfill his campaign promises. And Wednesday’s deal is a sign that he intends to follow through on that threat. (He clearly intended it as such: though Republican leaders also signed off on the deal, Trump specifically name-checked the Democrats in his speech in North Dakota a few hours later, pointing to the agreement as a sign that Washington was starting to work again.)

By working with Democrats, Trump can bypass the Republican leadership, GOP moderates, and personal foes like Sen. John McCain (R-AZ). However, it also means that he can cobble deals together between liberal Republicans and the Democrat minority, leaving conservatives out in the cold.

The only way to stop him is for Republicans to unite. By showing he can deal with Pelosi and Schumer, Trump may have found the one way of making them do so.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He was named one of the “most influential” people in news media in 2016. He is the co-author of How Trump Won: The Inside Story of a Revolution, is available from Regnery. Follow him on Twitter at @joelpollak.