The new Congress has officially been sworn in.

There’s a new shift in power, with Democrats taking control of the House of Representatives.

Nancy Pelosi has become the House Speaker once again, and the first and only woman speaker in American history.

“With a divided Congress, getting controversial bills passed becomes more difficult on things like immigration and health care,” Pelosi said Thursday.

“Divided government is different than unified government, so we're not going to be working off the president's or Republican's agenda for what to do,” explains Bill Fortier, with the Bipartisan Policy Center. “If we get laws passed, it's because we have some meeting of the minds and that's difficult.”

Both sides have expressed hope they can compromise on ways to lower drug prices and fix the nation's crumbling bridges and roads.

But things could hit a road bump.

Democrats promise President Donald Trump can expect a "different world," as they get more power.

“Controlling the House of Representatives, for Democrats, gives them the opportunity to really investigate the president or do oversight or highlight issues where they think he is falling down,” says Fortier.

President Trump warns investigations of him or his administration would lead to a "war-like posture."