Before The Donald was making political waves, there was the tea party doing the same. Now the question is whether these two wave-makers can come together.

It won’t be as easy as some think. Though the impulse behind the two movements is roughly the same—bust up the political system, starting from within the Republican Party—the differences are significant. The tea party is largely a movement of small-government, Constitution-loving conservatives. Donald Trump’s Trumpism is largely a populist movement, led by a man whose conservative bona fides are questioned and who seems inclined to expansive presidential power in some areas.

That leaves a gap, and tea-party activists are trying to figure out whether and how it might be closed. “The thing about the Trump movement is it’s about Trump,” said Jenny Beth Martin, chairman of the Tea Party Patriots Citizen Fund. “We’re about principles.”

The tea-party movement arose in 2009, initially as a response to government rescues of financial firms. Later it was fueled by opposition to the Affordable Care Act—known as Obamacare—and became a receptacle for antitax sentiment and general mistrust of government.

Its main targets were President Barack Obama and his administration, but establishment Republicans became the casualties. Utah Sen. Robert Bennett, Indiana Sen. Richard Lugar and House Republican leader Eric Cantor all had their congressional careers ended by tea-party rivals who branded them as too meek.