Five things that would change in a GOP-led Senate

1. Will President Obama’s big achievements be hollowed out?

Republicans say that if they gain control of Congress they will start chipping away at two of the Obama administration’s biggest victories: financial reform and healthcare. 

The GOP could well decide against attempting another full repeal of the Affordable Care Act. But its members would probably try to eliminate the much-discussed medical device tax. They might also look at nixing the employer mandate.
The Dodd-Frank financial law is high on the hitlist of GOP lawmakers. They want to ease capital requirements for large insurance companies, create both a board of directors and a new inspector-general position for the Consumer Financial Protection Bureau, and streamline a process for banks deemed too big to fail. 

More generally, Republicans have made it clear that Obama’s regulatory agenda is a prime target.

With control over the budget and appropriations process, Republicans could cut off funding that is needed to implement or enforce regulations — including the EPA’s carbon-pollution standards for power plants, which form a big piece of the president’s climate agenda. 

The GOP will also probably ramp up efforts to push through the Keystone XL pipeline and expand natural-gas exports.