A new interim redistricting map in Texas would give Democrats a good shot at winning three of the state’s four new House districts and could help them win the battle to create new Democratic-leaning congressional districts nationwide in the decennial round of redistricting.

Rep. Lloyd Doggett (D-Texas), left, and his fellow Democrats got a big break when a three-judge panel in Texas drafted an interim map for the 2012 election. That map is much better for Democrats than a GOP map that is being challenged in the courts. (AP Photo/J. Scott Applewhite)

The map the judges produced should swing at least two seats in Democrats’ favor, and possibly more, compared to the GOP map. And those two seats tip the scales toward Democrats when it comes to the nationwide battle to create new districts they will be favored to win in 2012.

The Post’s Redistricting Scorecard now shows Democrats with a net gain of at least two new House seats they should win nationwide, while Republicans are losing at least one seat, according to projections.

At last check, both sides had created roughly the same number of new seats that they could win — a virtual tie. But that was assuming Republicans would gain three seats in Texas. Now, with Democrats having a better map in Texas, they have an edge that Republicans will be hard-pressed to overcome in the remaining states that have yet to draw their maps.

Republicans could still conceivably gain seats in a few states like Florida, New York and Pennsylvania, but they would need to catch some breaks.

Republicans have been acknowledging for a while now that, despite their national ability to draw about four times as many House districts as Democrats, creating new ones they can win is difficult because they already have large advantages in the delegations of most of those states and the demographics won’t allow them to squeeze in any more GOP districts. Instead, the GOP has touted its ability to shore up its current members.

But the situation in Texas is nothing short of a setback for the GOP. That’s because, at least for the 2012 election, Democrats are now likely to have more new districts that are winnable than Republicans. (The Texas GOP’s map could still be instituted for the 2014 election.)

Here’s a closer look at what the Texas interim map looks like.

* The Republican map had made two of the four new districts — added thanks to population growth — into Republican-leaning ones and dismantled Rep. Lloyd Doggett’s (D) district so that Republicans could gain a seat. On the court-drawn map, Doggett is safe, and three of the four new districts are Democratic-leaning.

* Districts 27, 33, 35 and 36 are essentially the new districts (Republican Rep. Blake Farenthold, who currently represents the 27th district, seems likely run in the 34th instead), and three of those four seats went less than 45 percent for Sen. John McCain (R-Ariz.) in the 2008 presidential election. While the GOP may be able to compete for the new 35th district or possibly even the 27th, they are both Hispanic-majority districts, of which the GOP holds pretty few nationwide.

* The 35th, in particular, could be a battleground. It went 44 percent for McCain in 2008 and 53 percent for former home-state governor George W. Bush in 2004.

* Most incumbents were protected by the interim plan, but some still have plenty to worry about.

The 34th district is very friendly to Republicans, going 66 percent for McCain, but it seems quite possible that Farenthold would face a primary challenge there. Rep. Quico Canseco’s (R) battleground 23rd district remained about a 48 percent McCain district, so he will have a tough race.

And Rep. Michael McCaul’s (R) Houston-area district moved about three points toward Democrats, but is still a district McCain carried with 52 percent of the vote. Democrats have also suggested they may be able to target Rep. Joe Barton (D), but his district was still carried by McCain in 2008 by 54 percent of the vote.