The Republican wave that swept Democrats out of the majority in the Senate on Tuesday has taken away at least some of the muscle behind congressional efforts to bring sweeping surveillance reform.

Sen. Mark Udall, D-Colo., one of the toughest critics of the National Security Agency, lost his reelection bid to Rep. Cory Gardner, R-Colo. And Sen. Patrick Leahy, D-Vt., author of the Senate’s USA Freedom Act, a leading proposal to rein in government surveillance, will lose his post as Senate Judiciary Committee chairman in January when the chamber comes under Republican control.