(Updated 11/13 5:55 p.m. ET)

After a 2012 election that left big Republican money reeling, the biggest players on the right have a lot to celebrate. According to our tabulation of outside spenders’ return on investment, the comeback kids of 2014 turn out to be the U.S. Chamber of Commerce and the Crossroads fundraising combine. Results for the Democrats: not so impressive.

The chart below shows the top 20 highest spending outside groups in the midterms and their success rate so far.

Two years ago, when we took the post-mortem of the presidential-year elections, powerhouse conservative spenders like Crossroads GPS, American Crossroads and the U.S. Chamber of Commerce had almost nothing to show for the tens of millions of dollars they funneled into that campaign. In 2014, conservatives turned the ship around, drubbing their liberal rivals in a year in which independent groups on both sides dropped unprecedented amounts of money.

The three conservative organizations mentioned above all had success rates under 20 percent two years ago. This year? Each group batted .800 or above. With several races remaining to be decided, the National Republican Senatorial Committee also boasts a 94 percent success rate.

No matter what its ideological leaning, outside money is definitely not bullish on politicians. In the chart below, the size of the circle represents the size of the expenditure — and by far the most money went to negative advertising. Hover over each circle to get more information on the spender.

The nature of midterm elections had a big impact on the ratings. In 2012, most of the independent spending was concentrated on one race — the White House — so Obama’s re-election meant that millions in conservative dollars had been spent in vain. This cycle, the action has been spread out, but the results are nearly equally lopsided.

For new mega donors on the Democratic side, the outcome is a rude awakening.

Tom Steyer, who spent more than $70 million of his own money launching his own super PAC, has little to show for his efforts. Steyer’s NextGen Climate Action, an environmental messaging machine that opposed Republicans in close races across the country, lost major battles against Cory Gardner in Colorado and Joni Ernst in Iowa, both now senators-elect.

The results were equally grim for all groups that followed the Democratic battle plan: Senate Majority PAC — founded by former staffers to Sen. Harry Reid and fueled by a core of liberal donors including Steyer, Fred Eychaner and Michael Bloomberg — acted like the DSCC’s right arm in its strategy — and got walloped as a result.

Of course, there are some anomalies in this narrative. Not all conservative groups had a banner year. The Ending Spending Action Fund put most of its efforts into the two Senate races that Democrats managed to save: New Hampshire and Michigan. And while the National Rifle Association scored extremely well, the pro-gun control Independence USA super PAC, largely funded by Bloomberg, posted an ROI fit for the Wall Street billionaire: 100 percent. The group focused the bulk of its general election spending — $3.8 million — helping to re-elect Robert Dold, an Illinois Republican, to the House seat he lost two years ago. The PAC also made smaller expenditures to help re-elect Sen. Al Franken, D-Minn., and Rep. Michael Fitzpatrick, R-Pa., both of whom faced far less competitive races.

Likewise, some groups that eschewed a party line ended up doing quite well. The National Association of Realtors, which is unsurprisingly focused on mortgage and insurance legislation, supported candidates on opposite ends of the political spectrum, from Republican Senate Leader Mitch McConnell to Democratic Sen.-elect Gary Peters. Nearly all of Realtors’ candidates won.

Another trade association, the American Chemistry Council, has been active backing incumbents on both sides of the aisle this year. But in the closing days of the campaign, the group focused its money largely on media for Republicans in four hotly contested races: Joni Ernst in Iowa, Mike Rounds in South Dakota, Pat Roberts in Kansas and David Perdue in Georgia. The results gave the Chemistry Council a 100 percent success rate for its $1.7 million investment.

When examining these results there are a few important caveats to consider:

Spending on primary races was not included in this analysis.

Additionally, we can only report what we see. These figures only capture the outside money that is disclosed to the Federal Election Commission, so-called independent expenditures that expressly support or oppose a federal candidate.

For this analysis, we categorized “successful” spending as money either spent supporting a winning candidate or opposing a losing candidate in the general election.

These percentages only cover races that have a conclusive winner. So, money spent on races that go to runoffs, or are still too close to call, are not factored into our return on investment study. We will update it as results come in.

At this point the results of three House races — one in Arizona and two in California — remain in doubt. Louisiana, the target of $16 million in spending by outside parties so far, will not be decided until that state’s December runoff; two Louisiana House contests are also headed to runoffs.

To download a complete file of groups spending in the general election and their return on investment, click here.