House Minority Leader Nancy Pelosi continues to insist that Democrats can pick up 17 seats in the November to retake control of the House. She also insists that fallout from ObamaCare will not hurt Democrats this fall. Setting aside that delusion, the Democrats’ chief problem isn’t ObamaCare. It’s math.

There are 188 House seats that at least lean Democrat, according to the Cook Political Report. To win a majority, then, Democrats have to win all of these seats and win 30 seats that lean Republican. That’s a tall order in any election cycle. Unless President Obama’s approval ratings climb in the coming months, it is all but impossible.

Now, just because a congressional district is rated “R” or “D” doesn’t itself preclude a candidate from the opposite party winning an election. Elections often turn on the strengths of individual candidates. The challenge for Democrats, though, is there are few Republicans in Democrat-leaning districts. Just 5 Republicans represent districts that lean Democrat. Three Republicans represent districts that are evenly split between the parties.

Democrats, however, hold 14 congressional seats that lean Republican. They hold 5 seats that are considered “even.” Is it likely that elections in the middle of President Obama’s second term will create a wave that allow Democrats to win a host of Republican-leaning districts?

In 2010, when a Republican wave captured 63 seats to take control of the House, only 11 of those were in Democrat-leaning districts. One could argue that Republicans underperformed in 2010, largely recapturing seats that were Republican. Most of these seats have become even more Republican as a result of redistricting.

Republicans taking control of the House in 2010 overshadowed the rout Democrats suffered in state houses. Prior to the 2010 election, Democrats controlled 32 state houses and Republicans just 16. After those midterms, the power flipped, with Republicans winning 30 state houses and Democrats controlling just 18. Republicans also, for the first time since the 1920s, had a majority of state legislators.

As a result, Republicans had complete control of the redistricting process in many states. They used this to solidify the number of safe Republican seats. Republicans go into the elections now with 199 “safe” Republican seats, requiring just 19 seats that lean Republican for a majority. If the GOP simply wins the districts carried by Romney in 2012, it would have an 11 seat majority. Democrats have just 162 seats considered “safe.”

It should be noted that the Cook Political Report bases its partisan rating of a district on votes in Presidential election years, not midterm elections. It measures the vote for a presidential candidate in the district relative to the national vote. As we’ve seen in at least the past 5 midterm elections, the outcome can be very different than the vote in a presidential year.

So, it is entirely possible that the Democrats’ already weak position is overestimating their election prospects. Of course the election is eleven months away and the Republicans are preternaturally disposed to try to snatch defeat from the jaws of victory. Republicans, though, can’t overcome math. Democrats need a wave bigger than 2012. That possibility crashed on October 1, 2013.