It's a Right vs. Left divide, not Dems vs. GOP. Many Democrats represent conservative, not progressive districts. If 15 Dems in the Senate would vote their party platform, gun control would pass.
If so many Dems weren't conservative, the Iraq war approval wouldn't have passed, Guantanamo would be closed, Wall Street crooks would be in jail, Bibi Netanyahu wouldn't get 22 congressional standing ovations, the war on terror and drone attacks would be winding down, civil liberties would not be threatened, austerity wouldn't be on the table, etc. etc. No wonder the GOP wants to vote by district instead of state. It's why the GOP has moved even farther to the right and the Dems have moved across the center line.
The GOP has Fox News promoting their ideology. The Dems have MSNBC, but MSNBC represents the conservative wing of the Democratic party. There's nothing on there that's progressive. They love the new Obama sellout on Social Security. They still think austerity is wonderful. Who in the main stream media speaks for progressives? Only the polls indicative some progressive sentiment.
So, what does it look like for 2016? Another Clinton that voted for Iraq, loves sanctions and hegemony, loves Bibi, hates Iran, likes Wall Street and globalization. Hardly a progressive. Even Ron Paul is further left than the Democratic Party on foreign policy and military entanglements. It looks like more of the same for a long while.
Read this link and see the evidence that right wingers still run the country.