WASHINGTON (AP) -- Republicans' grip on all levers of power stands as a mandate to the GOP-led Congress, which will move swiftly to try to undo eight years of outgoing President Barack Obama's agenda.

With Republican President-elect Donald Trump just weeks away from assuming office, GOP lawmakers plan to open the 115th Congress on Tuesday and immediately take steps to repeal Obama's health care law. Beyond that, they'll look at a tax overhaul, reversing Obama-era environmental regulations and other conservative priorities.

Republicans will face some obstacles. House Minority Leader Nancy Pelosi says Democrats "stand ready to fight vigorously" to protect health care and other priorities, and Republicans will have to compromise with Senate Democrats to move major legislation through that chamber.

A look at what the 115th Congress will be up to in 2017:

---

NEW MEMBERS

New members of the House and Senate will be sworn in on Tuesday, the first day of the new Congress.

In the Senate, five Democrats and two Republicans will be sworn in for the first time, joined by returning members who won re-election in 2016. After those members are sworn in, there will be 52 Republicans, 46 Democrats and two independents who caucus with the Democrats.

The House will have 52 new members - 27 Republicans and 25 Democrats. There will be 241 Republicans in the House and 194 Democrats.