“ Democrats are being outspent by Republicans and their allies in Iowa,” says a press release this week from the Senate campaign of Democratic Rep. Bruce Braley.

Braley, whose Senate race is a dead heat, also complained to small-dollar donors on his email list Thursday that “the Koch brothers have special interest spend-and-attack strategy to try and buy a victory in Iowa” for his Republican opponent.

Sen. Kay Hagan, D-N.C., sends emails to supporters like this nearly every day, complaining that Republican interests such as those aligned with Karl Rove and the Koch Brothers “have now spent more than $27 million against me.” She adds, “[W]e’re up against more Koch, Rove, outside attacks than ever before.”

Given such complaints, you might think Democrats like Braley and Hagan are being overwhelmed by outside spending. You'd be wrong — they're doing just fine.

In the 11 Senate races where independent expenditures by outside groups are a significant factor, Democrats have spent about $18 million more on aggregate than the Republicans. When it comes to negative ads, the kind Democratic candidates complain about so often, their advantage is even larger. Left-leaning groups have spent about 70 percent more on negative ads than their GOP counterparts.

According to the latest totals from the FEC, compiled at OpenSecrets.org, Braley has enjoyed a $200,000 advantage from independent expenditures by outside groups in his Iowa Senate race so far. Democratic outside groups have spent $9.5 million just on negative ads trashing his opponent, Republican state Sen. Joni Ernst.

Hagan has it even better. Left wing outside groups have run more than $15 million solely in negative ads to beat up her opponent, Republican state House Speaker Thom Tillis. That makes him the most vilified Senate candidate in America. The runner-up for that distinction is also a Republican, Rep. Cory Gardner, who is running for Senate in Colorado. He now leads in the most recent polls, even though outside Democratic groups have spent $12.9 million trashing him, which is more than double the amount outside groups have spent attacking his incumbent opponent, Sen. Mark Udall.

Only two Republicans in major Senate races this year have the advantage in terms of independent expenditures, Sen. Mitch McConnell of Kentucky and David Perdue of Georgia.

Democrats will protest that independent expenditure totals don't tell the whole story. Millions are also spent in these races on issue ads by groups that don't have to disclose their numbers yet. But an analysis by Wesleyan University shows that they aren't quite as big or overwhelming as Democrats suggest. Even the largest such group, Americans for Prosperity, had spent only $16.7 million on airtime as of September 4, a significant amount of which was dedicated to House and gubernatorial instead of Senate races.

The bottom line is that Democratic candidates for Senate don't lack outside money, and would still be doing just fine if they stopped whining about it.