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.