It is very clear Republicans have the edge in this cycle. Gerrymandering virtually assures GOP control of the House, and Democrats have basically ceded the Senate races in South Dakota and West Virginia. Democrats are very vulnerable in NC, Louisiana, Arkansas, and Alaska, and could even lose Michigan and Iowa given the right circumstances. In contrast, there are virtually no GOP Senate seats the Dems can pick up this cycle.
The gerrymandering enacted by the GOP will reduce their losses in the house but will not stop them.
The senate picture for the GOP looks pretty good right now; they stand to gain 5 or 6 seats but that will likely quickly reverse as we the primary season takes off early next year. Remember; all of those republican senators elected in 2010 will be vulnerable in 2016, we might have another Democrat super-majority in 2017.
The 112th Congress, with the GOP controlling the House, has been the worst in my lifetime. I'm 53. If the House actually manages to do something, it's only after too much time has lapsed (consider their Hurricane Sandy Aid vote) ... Or it's something we don't need (think the default attempt) ... Sad. The House hurt over 6Ms students recently when they allowed student loan rates to increase. Who is going to address & correct the problem? The Senate, where Dems are in control.
By comparison, the 111th Congress (w/Dems in control of both) was the hardest working & most prolific one in 40 years! Americans saw action & got results. That's what people are looking for from D.C. -- actual service.
In 2012, Republicans lost seats in the House. They made no gains the Senate. Many who lost were in the Tea Party. A year later, the GOP is still embracing the TP -- no change there. The party in-fighting is also frustrating. If they cannot get on the same age as a political party, how can they possibly run the nation? Every time there is a setback, or move that hurts the average American, it seems you can trace the problem to Republicans. People are fed up. I was a Reagan Republican & I can scarcely believe it. Reagan certainly wouldn't!
In 2014, America will vote more Democrats into office. Will it be enough for Democrats o take full control? I can only hope.