I happened to be in the U.S. Capitol when the Citizens United decision came down four years ago. Democratic lawmakers greeted the decision with a mutually reinforcing mixture of fury and fear. The decision, everyone agreed, would unleash a tsunami of corporate and plutocratic money into politics, giving Republicans a huge spending advantage. "This is the end of our party," wailed one Democrat, aware he was going a tad over the top.

Things haven't worked out as expected. In 2012, Mitt Romney did not have a spending advantage over Barack Obama. According to the Center for Responsive Politics, very few publicly traded corporations made political donations.

During the 2012 campaign cycle, news articles began appearing in local papers reporting that it was sometimes Democratic groups who were making the most of the post-Citizens United landscape. The Center for Public Integrity looked at campaigns in 38 states in 2012. Democratic-leaning groups outspent Republicans by more than $8 million.

This year, the same sorts of articles are appearing. A Politico analysis in September found that the 15 top Democratic-aligned committees outraised the 15 top Republican ones by $164 million. Based on data from the Center for Responsive Politics, Democrats have more money than Republicans in most of the tightest Senate races: Colorado, Alaska, Arkansas, Georgia, Iowa, Louisiana, Minnesota, North Carolina, New Hampshire and Virginia.

Karl Rove has been shaking the Republican donor base, arguing that his groups are being outspent. A September study by his super PAC, American Crossroads, found that Democratic candidates have reserved $109 million in television advertising time before Election Day, while Republicans have reserved $85 million.

So was the furor about Citizens United misplaced? Will Democrats end up winning the political spending wars, thanks to their own plutocratic donor base?

Well, the situation is complicated. The first thing we know about the post-Citizens United era is that it has accelerated a pre-existing trend: Each year more money flows into campaigns. Spending this cycle is more than double what it was at this point in 2010 and four times higher than it was in early October 2006.

Second, the decision has not scared away small donors, as many feared. A study by Douglas M. Spencer and Abby K. Wood suggested that smaller donors were just as likely to be active after the decision as before.

Third, many of the Democrats' advantages in spending this year are temporary. A wave of Republican money is expected in the next few weeks. Democrats do have an advantage in the donations made to super PACs, which have to report their donors. But Republicans lead in donations made to 501(c)(4) groups, which can keep the names of donors secret.

The final, most important effect of Citizens United is that it will reduce the influence of money on electoral outcomes. Yes, that's right. Reduce.

Remember, money is quite important in local races, with unknown candidates.

But money is not that important in high-attention races. Every year we get more evidence suggesting that campaign spending does not lead to victory. In 2012, the Koch brothers spent huge amounts of money to pathetic effect. Rove's American Crossroads dumped $117 million into the 2012 election. More than 90 percent of it was spent on candidates who ended up losing.

And money is really not important when both candidates are well-financed. After both candidates have hit a certain spending threshold, the additional TV commercials they buy are just making the rubble bounce. The economist Steve Levitt has found that if you cut a campaign's spending in half, and held everything else constant, the candidate would only lose 1 percent of the popular vote. If you doubled spending, the candidate would only gain 1 percentage point.

We're now at a moment when a fire hose of money is trying to fill the same glasses of voters. That means every plausible Senate candidate and almost every plausible House candidate has more than enough money to get his or her message out. What matters more is the quality of that message and the national mood. If Democrats exceed expectations this year, it will be because of the reasons Ashley Parker and Nicholas Confessore identified in a recent New York Times article: because their message is better defined.

The upshot is that we should all relax about campaign spending. We should worry more about America's rich. Some people who are really smart at making money are apparently really stupid at spending it. This year, the big spender is a hedge-fund manager named Tom Steyer. He could have spent $42.7 million paying for kids to go to college. Instead, he has spent that much money this year further enriching the people who own TV stations. What a waste.

David Brooks' column is distributed by the New York Times News Service.