We wrote Monday about how Republicans are playing a surprising amount of offense in the battle for the House in 2012.

While Democrats have spent 70 percent of their funds on GOP-held seats, Republicans have spent less than half their funds defending those seats. Instead, Republicans are going after a bunch of Democratic-held seats and hoping, for lack of a better sports cliche, that the best defense is a good offense.

And wouldn't you know it? The Sunlight Foundation has a chart making precisely our point.

Here's the chart, comparing independent expenditure spending from both the House Republicans' campaign committee and the House Democrats'.

The chart basically shows which side is spending more in which races. The higher up a race is on the chart, the more Republicans are outspending Democrats. The lower a race is, the more Democrats are outspending Republicans.

As you can see, almost all of the races in which Republicans are spending more are for Democratic-held seats (denoted by the blue text), while almost every race where Democrats are spending more is for a seat held by a Republican.

And while Republicans are spending more on races that lean Democratic and less on races that lean red, Democrats are spending more on districts that lean Republican than lean blue.

In a lot of ways, that's to be expected. After all, both sides want to play offense.

But the degree to which their ad spending has differed so far shows two pretty different views of the playing field -- and a potential for some significant shifts in the 2012 election.

Both sides are opening themselves up by getting outspent in some of their most vulnerable districts, and if the election starts tilting one way or another, it could leave the unfortunate side at a significant deficit.