Exhaustive (and exhausting) list of obstacles to Democratic victory in 2014.
In no particular order...
1. Gerrymandering. Republicans have gone about gerrymandering with a strategic focus similar to business investment - using each round of it as a means to expand rather than merely protect what they have. The results have been an increasingly undemocratic partisan proportion that in no way reflects the American electorate, at times - like 2012 - resulting in GOP majorities in legislative bodies when the majority of voters had voted for Democrats.
2. Prison districting. This is a long-standing issue whereby rural, strongly conservative districts choose to locate prisons in their territory. The inmates of these facilities, most of whom cannot vote or wouldn't vote anyway, are then counted as constituents, resulting in quite a few Republican districts that would not otherwise exist or would have to be combined into one. I've read studies claiming that the GOP would not have won a single Congressional majority in the past three decades without this undemocratic phenomenon.
3. Jim Crow 2. Thanks to 5COTU5's ruling striking down key portions of the Voting Rights Act, and the high likelihood they will make further lawless decisions attempting to decide elections in favor of the GOP in advance, it is extremely likely that minority voters will face obstacles to voting unprecedented in generations. This only compounds the demographic tendency of low-income and minority voters to sit out midterm elections. Remember, that Tea Party operative who threw out voter registration forms in 2012 was never prosecuted by the Republican prosecutor in that area, so expect such tactics to be implemented on a massive scale this time around.
4. Perverse Blame. Bizarre as it seems, some people seem to think Congress is currently run by Democrats or even the President, and that they can just wave a magic wand and overcome absolute obstructionism. The Senate, which does have a Democratic majority, still has to deal with filibuster obstructionism, and obviously cannot dictate anything to the House.
5. The media is full of unhinged right-wing propaganda. But what else is new?
6. 5COTU5's lawless decisions turning elections into auctions. Since the rich are largely Republican, and since more of the middle and lower classes sit out midterm elections, the GOP will simply buy their desired result through even more pervasive right-wing propaganda campaigns than normally flood the media. The truth will simply be shouted down and locked out, lies will be believed for lack of any sufficiently-scaled challenge.
7. A distracted / priority-incompetent left. Again, what else is new? Achieving something will always be less important to some people ostensibly on our side than self-satisfaction.
8. 5COTU5 can always pull another Bush v. Gore if all else somehow fails them. They have shown their willingness in the past to simply throw out and arbitrarily decide elections as they see fit, and their level of brazenness these days approaches infinite.
9. Outright election-rigging is likely in some areas. No matter how many advantages right-wingers have in a legitimate election, they will always prefer a guaranteed result. They've tried before, and they've succeeded often enough to reward their efforts. Every election cycle makes their efforts more organized and increases its scale. With a newly energized Tea Party / brownshirts at work on behalf of their millionaire masters to end democracy in America once and for all, and knowing 5COTU5 has their back, expect new depths of brazen authoritarianism to be plumbed.
So...what are you gonna do about it?
= new reply since forum marked as read
hesitate 1 nanosecond to overturn election results in favor of the GOP. They are crooked, vile, black rob(b)ed thugs! True ACTIVISTS, ones that have never exercised this level of legal slimeballery since Bush v. Gore. 
