With just less than a year to go until the 2012 election and most states having wrapped up their once-a-decade redistricting process, we’re starting to get a good sense about where the key House battles will take place.

Arizona Gov. Jan Brewer’s (R) effort to oust her state’s redistricting committee chairwoman was thwarted this week. And so the new map is expected to give Democrats a good opportunity to win seats. (Jack Kurtz/AP)

But which states?

Today we look at 10 states that could determine whether Democrats retake the House or the GOP holds its majority next year.

To the Line!

10. New Hampshire: This state isn’t on the Line because of anything having to do with redistricting since it only has two congressional seats. Recent history has shown the state to be a central national battleground, however. Both New Hampshire seats went Democratic in 2006 when the party won the majority and then flipped to Republican when the GOP retook the House in 2010. And both will remain competitive next year, no matter how they are drawn. If Democrats win one of them, they’ve had a good night. If they win both, they’ve probably reclaimed the House again.

9. Ohio/Pennsylvania (tie): These states are really pretty similar so we’re lumping them together. In both states, the GOP is drawing the lines, but the current delegation is so heavily Republican that it’s hard to both add new opportunities and shore up their current members. Both states feature about five Republicans in swing districts that need to be strengthened. If the GOP can hold most or all of those seats on Election Day, they have probably done enough to hold the House.

8. North Carolina: The GOP targeted four – count ‘em, four – Tarheel State Democrats in redistricting and has a good chance against each. Here’s how the hierarchy goes: Republicans should be able to take Rep. Brad Miller’s seat, barring a real disaster. They also have a great chance to take Rep. Larry Kissell out. If the GOP can also beat Democratic Reps. Heath Shuler and Mike McIntyre, they have probably held the House with ease.

7. Texas: Democrats got a huge break here when a Washington, D.C., court declined to pre-clear the Texas GOP’s aggressive redistricting map last week. The ensuing court battle means a San Antonio-based panel of judges will draw an interim map for 2012 – a map that is expected to move this from a state where the GOP would have gained three seats and Democrats one (the state is adding four new seats) to one where Democrats could gain four seats. Four seats would be huge for Democrats, given that they only need 25 nationally to retake the majority. At the same time, we have no idea what kind of map the judges will draw, and they may protect incumbents.

6. Colorado: A Denver judge last week picked a map that had been drafted by Democrats, which means this is a big opportunity for the party. Rep. Mike Coffman (R-Colo.) is newly imperiled, and freshman Rep. Scott Tipton (R-Colo.) got a tougher district as well. Beating Coffman would be a particularly good sign since Democrats are trying to make the 2010 election about the extremeness of GOP incumbents. Coffman is very conservative but he’s also a proven campaigner with three statewide wins under his belt. If he loses in a district that still has a slight conservative lean that bodes poorly for GOP freshmen without such a track record in sometimes tougher districts.

5. Arizona: Guess what? Another break for Democrats here, after the state Supreme Court on Thursday reinstated the chairwoman of the state’s bipartisan redistricting commission. Gov. Jan Brewer (R) and the GOP-led state Senate had removed the chairwoman because they saw the map the commission drafted as favoring Democrats. And indeed, Democrats will have chances. The map makes the state’s new district a Democratic-leaning one, endangers freshman Rep. Paul Gosar (R-Ariz.) and makes Rep. Gabrielle Giffords’ (D-Ariz.) district safer in case she can’t run for reelection. If Democrats can win all three of those seats, it’s going to go a long ways toward regaining the majority.

4. New York: Three people have complicated the Empire State’s redistricting process: Gov. Andrew Cuomo (D) and special election winners Kathy Hochul (D) and Bob Turner (R). Cuomo has suggested he might veto a partisan-drawn map, which could throw many seats up for grabs. The wins by Hochul and Turner earlier this year, meanwhile, complicated the calculus for which two seats will be eliminated. (The state is losing two seats due to population growth that lagged the national average.) But at the very least, plenty of Upstate districts have changed hands in recent years and many of them will continue to be competitive regardless of how the map is drawn.

3. Illinois: Democrats really reshuffled the map here and could win three, four or even five new seats. Democrats should be able to take seats left behind by Reps. Joe Walsh (R) and Adam Kinzinger (R), who are running in primaries against other GOP incumbents. They should also be able to beat Rep. Bob Dold (R) in the new 10th district. Beyond that, if they beat Rep. Bobby Schilling (R) they’re having a good night, and if they beat Rep. Tim Johnson (R) they may be able to win the House.

2. California: The nation’s biggest state has been an electoral afterthought for some time, going a nearly a decade with only one congressional seat changing hands between 2002 and 2010. That won’t happen again. At least three GOP-held seats are likely to go Democratic in the newly reshuffled map crafted by the state’s new citizen’s redistricting commission. But Democrats think they can run up the score even more, while the GOP strategists believe they can win Democratic-held seats elsewhere to even the score. We could see the results spanning from a total wash to Democrats gaining eight seats. Anything on the top end of that scale would be a major Democratic win.

1. Florida: This remains the biggest question mark still left in redistricting: Just how potent are Florida’s new redistricting standards? The constitutional amendments passed by voters last year try to rein in partisan gerrymandering. Republicans insist they will still be able to add two GOP-leaning seats on top of their 19-to-6 advantage in the state’s delegation. But if the amendments have teeth, Democrats could gain back a handful of seats – as many as five or six, according to their estimates. That’s a big swing. Of course, it all depends on what the courts do and so far the courts have been pretty good to Democrats.