Whether you think that Democrats lost the House and a majority of state legislatures in 2010 because of a lack of improvement in the economy, the natural cycle of out-party gains in a midterm election, the clever use of Republican obstructionism to dampen economic performance, those damn liberals who didn’t clap loudly enough, or whatever, you cannot deny the lasting impact of that massive thumping. The Brennan Center has a report out today about post-2010 redistricting, and how it has tilted the map in favor of Republican control that may last regardless of the mood of the nation.

It’s the state legislative sweep for Republicans that matters here, more than the GOP takeover of the House. Because of those gains, Republicans controlled redistricting in 17 states controlling 173 Congressional districts, while Democrats controlled redistricting in just 6 states with 44 Congressional districts (four states with 21 Congressional districts featured split control of the process). Independent or politician-led commissions, state and federal courts, drew the maps for 15 states, and another 7 have no Congressional redistricting process because they only have one at-large seat (South Dakota, North Dakota, Wyoming, Vermont, Delaware, Alaska, Montana). The only state that the Brennan Center didn’t model is Texas, because the outcome of the redistricting process is up in the air, with the legislative Republican-drawn maps ruled invalid by a court, and court-drawn maps being used for the 2012 cycle. If anything, the inclusion of Texas would make this look even worse, since their maps, even with the court-drawn process, are seen as more favorable to Republicans relative to the voter registration and demographics of the state.

The Brennan Center found, unsurprisingly, that “where they controlled the process, partisan actors – both Democrat and Republican – used redistricting to increase their political advantage.” This is what makes the 2010 election so critical. The report finds that there are now 196 so-called “safe” seats in Congress, which is actually down from 207. More of those safe seats, defined as where one party receives over 60% of the two-party vote in elections, are actually on the Democratic side (116 safe Democratic seats, versus 80 safe Republican seats). But this is precisely the issue. Republican mapmakers packed Democrats into these overwhelmingly safe seats, making far more “likely” GOP districts (defined as where one party routinely receives 55-60% of that two-party vote). There are 99 likely seats for the GOP across the country, relative to just 52 Democratic ones. Add in the greater number of “marginal” Republican seats, and you have the following situation. Before redistricting, the expected Congressional makeup, based on the partisan lean of the district, was 230-205 in favor of Republicans. Now it’s 241-194, a difference of 11 seats moving to the GOP.

Here’s a perfect example where you can see the mapmakers’ hands at work. Before redistricting, in Republican-controlled states, there were 48 “marginal” districts, split somewhat evenly, with 29 marginal Republican seats and 19 marginal Democratic ones. After redistricting, the marginal seats reduced to 36, and an astounding 35 of them are marginal Republican.

This can obviously shift: the partisan lean did not hold in 2006 and 2008, for example, when Democrats held the chamber by a wide margin. And demographic changes can often turn a marginal Republican seat into a marginal Democratic one, and so on. But locking in this advantage just based on drawing the district lines gives Republicans a significant leg up. Barring a wave election, the lines are drawn to give them control of the House. And that’s because more Republican bodies controlled the redistricting process, a direct result of 2010.

You can see this in the reversion to the mean of the various models for predicting the House elections. Now that polling at a district level is being taken into account, rather than generic polling that just shows which party voters prefer for Congress, you can see the effect of redistricting. Virtually nobody now predicts Democrats to take back the House. They see Democratic gains, owing to the changes in the national landscape. But it would take a true wave to get the 25 seats necessary for a partisan takeover.

Whatever the reason for the disastrous 2010 elections, we will feel its effects for a long time. Speaker Boehner in control of the gavel for another term, when key decisions will have to be made in Congress on spending and taxes, makes for what is likely to be another depressing term from the standpoint of responsible governance.