Things are about to change in a big way in Washington.

Democrats will take back control of the House for the first time in eight years at noon ET Thursday, putting an official check on President Trump’s powers and setting up what could be an increasingly acrimonious two years in the nation’s capital as they square off with the bellicose president.

Democrats will have 235 seats in the House, enough to block any GOP legislative proposals and a seat at the table in all legislative functions. Their new majority will also play a key oversight role of the president, with multiple committees champing at the bit to start investigating potential malfeasance committed by the Trump administration.

Renewed congressional oversight could trigger massive fights between the House and the administration over executive privilege as Democrats go digging into various White House actions, as well as the departments and agencies. The newly renamed House Committee on Oversight and Reform (dropping Government from the name), House Intelligence Committee and House Judiciary Committee are all expected to play key roles in investigating the administration, something the GOP-controlled House willfully refused to do. Their subpoenas won’t be limited to solving whether Trump’s campaign colluded with Russia during the 2016 election, either.

Rep. Nancy Pelosi (D-CA) is all but guaranteed to take back the speaker’s gavel, making her the first person to return to the speakership since Sam Rayburn did so back in 1954. Pelosi, 78, achieved this feat by cutting a deal with Democrats who opposed her return by promising to serve only two more terms as her party’s leader.

Governing in the minority tends to be easier — it’s a lot simpler to keep one’s party united against a common foe than to get members to agree on positive policy. That’s already been seen as Democrats from across the spectrum have stood fast against giving Trump money for his border wall, pressuring Trump to back off in order to end the ongoing government shutdown.

But Pelosi had to fight to get back to the speakership, and there are signs that she’ll have to keep working hard to keep both the left and center flanks of her party happy.

Even after Pelosi’s deal with a group of less than two dozen House Democrats secured her speakership, a handful of freshmen from tough districts have said they’ll vote for someone else on the floor as they keep one eye on the next election. On the other side, a restless group of progressives led by freshman Rep.-elect Alexandrio Ocasio-Cortez (D-NY) are threatening to vote against Democrats’ rules package on Thursday because of a provision requiring bills to be deficit-neutral, known as PAYGO or “pay as you go,” the latest sign that they’re not going to bow to leadership.

With 2020 right around the corner, Pelosi will also have to help shield the dozens of newly elected Democrats in districts Trump carried in order to keep the House in Democratic control after the next election.

Things could get increasingly complicated once special counsel Robert Mueller’s report is completed. It’s unclear what the report will contain, but Pelosi will likely have to manage competing impulses between progressives who see impeachment as a viable option (58 already voted to impeach Trump more than a year ago) and more moderate members wary of playing the ultimate card with a GOP Senate unlikely to convict — and their own reelections on the line.

But for now, a relatively unified Democratic Party will be able to block some of Trump’s biggest goals and for the first time will have subpoena power to investigate his administration. And Pelosi will once again run the show.