Democrats are banking on the idea that the same tea party bent that swept Republicans into the majority in 2010 will sweep them out in 2014. The gridlock that House conservatives have contributed to and the policies they have latched onto make them targets. At least, so goes the Democratic thinking.

That’s the 20,000-foot view. Zooming in a bit lays bare the fact that even if the national conversation is focused on the tea party, the challenge of winning back the majority is a hard one.

It’s going to be very difficult for Democrats, plain and simple. Redistricting has led to a polarized House map with more Republican-leaning districts and fewer swing districts that typically are the ripest candidates for flipping party control. Democrats also have some vulnerable incumbents of their own to shield from the GOP.

And history isn’t on their side, either. In the past century, only one president has gained seats in his second midterm: Bill Clinton in 1998. But even then, the shift was modest. Democrats netted five House seats that year — less than a third of what Democrats need this time around — and Republicans retained their majority.