Obama, Congress Clash over Pipeline, Health Care

The first day of the new Congress brought the first clash between President Barack Obama and Republican leaders.

It came just moments after Republicans took control of the Senate.

The White House immediately vowed to veto their first bill, a measure approving construction of the long-stalled Keystone XL oil pipeline.

Another top priority for the GOP is scaling back Obamacare. For example, Republicans want to change the law's definition of a work week, bumping it from 40 hours to 30 hours.

The idea surfaced after many employers began slashing worker hours to avoid paying for health care under the new requirement of the president's law.

The first black female Republican in Congress is just one of many who say they will push to replace Obamacare.

"I was elected by my district to make sure that we get the decision-making back in their hands," Rep. Mia Love, R-Utah, told ABC News "This Week."

"And I've said I want to do everything I can to repeal and replace it (Obamacare) with something that is functional, and get broad free market healthcare reforms, and that's exactly what I'm going to do," she said.

The president has vowed to block any attempt to repeal his signature health care law.