Republicans only needed six seats to take control of the Senate, but they garnered many more in Tuesday’s midterm election. This could signal major changes on Capitol Hill in the next two years.

In Senate races in Alaska, Arkansas, Colorado and North Carolina, Democratic incumbents were vanquished. In other closely-watched Senate elections–those in Georgia, Iowa, Kansas, Kentucky and South Carolina–Republicans were also elected or re-elected. Louisiana Sen. Mary Landrieu, a Democrat who assumed office nearly two decades ago, will now face a runoff against Republican Bill Cassidy. And it’s too soon to tell who will take Virginia in the contest between Democrat Mark Warner, the sitting senator, and Republican Ed Gillespie. At press time, they are nearly tied at a 0.6 percent margin. Even if Landrieu and Warner hold on to their seats, Republicans will still control the Senate. The G.O.P. also maintains its majority in the House.

Republicans fared well in governor races, too–even in blue states like Obama’s own Illinois, where Republican Bruce Rauner was elected, and in Massachusetts, where voters elected Charlie Baker, their first Republican governor since Mitt Romney declined to run for reelection in 2006. Obama held a press conference today about an Election Day that’s being widely described as a referendum on his presidency.

Kentucky Sen. Mitch McConnell (R) won reelection with a handsome lead over Alison Grimes (D). McConnell will become the Senate majority leader. On Monday, he told TIME that he won’t attempt to shut down the government, as Republicans have done in the recent past, and that he’s not looking to repeal Obamacare–at least not fully. He does prioritize the approval of the Keystone XL pipeline, and his party now has filibuster-proof way to see it through. Obama–who’s avoided making a clear statement on his position on the pipeline–could, of course, veto such legislation. But that doesn’t mean Congress can’t find a way to include it a bigger energy bill.

And what about immigration? As my colleague Julianne Hing writes, immigration reform advocates and national Latino groups are calling on Obama to use his executive power to protect undocumented immigrants from deportation. The president delayed taking such action until after the election, betraying a promise he’d made earlier this year that he’d do so before the election.

During today’s presser, he made a new promise that he’d take executive action before the end of the year. “There’s a cost to waiting,” said a conciliatory Obama today, citing losses to the economy as well as the separation of families. He added that he still hopes Congress will move forward on a comprehensive immigration bill. 

While undocumented immigrants can’t vote themselves, some raised nearly $2,000 in a grassroots effort in North Carolina to buy billboards criticizing Senator Kay Hagan, a Democrat. NC Dream Team placed Spanish-language billboards near popular intersections that read, “She started with licenses. Now she wants to take DACA. What will be next? Sen. Hagan is not a friend of immigrants.” The billboard refers to Hagan’s vote against undocumented immigrants receiving driver’s licenses and her vote against the DREAM Act in 2010, a decision that killed the legislation. On Tuesday Hagan lost her Senate seat to Republican Thom Tillis.