First up for Republicans: Expect this change

Strategist: Republicans must move on tax reform

Republicans will use their new-found power to take on a variety of issues, but none more so perhaps than tax reform.

Obamacare, the Keystone XL pipeline and immigration also will be high on the radar for a party regaining control of the House and the Senate, but changing the tax code is the most doable in the near term, said Greg Valliere, chief political strategist at Potomac Research Group in Washington, D.C.

"The big story next year, the showcase issue for the Republicans clearly will be tax reform," Valliere said Tuesday while speaking at the Schwab IMPACT conference in Denver. "I imagine that (House Speaker John) Boehner will say this is their top priority."

Republicans for years have been wanting to simplify the voluminous code, particularly with regard to its highest-in-the-world corporate rates, as well as providing incentives for companies to bring home profits that are stashed overseas.

Read MoreMidterm elections: A sure bet for investors?

Meanwhile, Democrats have been looking to stop the swarm of inversions—deals where U.S.-based companies buy another firm and change their domiciles to friendlier tax nations—that they say have been robbing the Treasury of much-needed revenue.