If Democrats manage to keep their grip on the U.S. Senate in November’s midterm elections, it won’t have been all about the money — but their success with fundraising will have helped.

Democratic candidates have an advantage in total money raised in nine out of the 10 Senate races that are rated as competitive by the nonpartisan Cook Political Report.

That’s shown in the below chart, which relies on filings to the Federal Election Commission by the candidates’ principal campaign committees and their joint fundraising committees with their parties.

A number of the Democratic candidates in battleground states could have a fundraising edge because they are “incumbents who aren’t needing to jump over all the hurdles of running for office for the first time,” said Michael Beckel, research director at Issue One, a nonpartisan watchdog group that aims to reduce the influence of big money in politics.

Beckel said those Democrats likely have an advantage over their GOP opponents in terms of their established fundraising machines and name recognition. And in some of the other competitive races, the Republican incumbent is retiring — which can also motivate Democratic donors, as it’s generally easier to win an open seat than knock off an incumbent, he said.

Five of the 10 competitive contests feature Democratic incumbents (the races in Georgia, Arizona, Nevada, New Hampshire and Colorado), while just two involve GOP incumbents (Florida and Wisconsin), and three have no incumbent as a Republican senator is retiring (Pennsylvania, Ohio and North Carolina).

The Supreme Court’s Dobbs decision in June that overturned Roe v. Wade, the landmark 1973 case that established a constitutional right to an abortion, is also a factor in this year’s fundraising.

A recent NPR/PBS NewsHour/Marist poll found 22% of Americans cite abortion as their top voting issue, up from 18% in July. Inflation is the No. 1 issue, with 30% of respondents pointing to high prices, but that’s down from 37% in July.

Related: U.S. inflation roars back in August, CPI shows, despite falling gas prices

“The issue of reproductive rights has motivated a lot of Democratic voters and a lot of Democratic donors,” Beckel told MarketWatch. “There’s a very strong fundraising appeal happening in the wake of this Supreme Court decision.”

Democratic campaigns are “trying to capitalize on that energy and motivate people to both turn out to vote and turn out to open their wallets to give them more campaign cash,” the Issue One expert said.

In order to codify Roe into law, Democrats would need to secure 60 votes due to Senate rules, with some of those votes potentially coming from Republican senators who sometimes buck their party. But Beckel said regardless of how many seats Senate Democrats control, if they’re in a majority, they’ll be able to do more on the issue of abortion than if they’re in the minority.

Democrats currently run the 50-50 Senate only because Vice President Kamala Harris can cast tiebreaking votes.

Related: Betting markets now see Democrats keeping their grip on Senate in midterm elections

While individual Democrats have largely outraised Republicans in the competitive Senate races, some key national Republican committees are faring better in attracting donations than their Democratic counterparts, as shown in the chart above.

Other Republican-affiliated players also are stepping in to help GOP candidates, whether it’s billionaire Peter Thiel or One Nation, a so-called dark money group that doesn’t disclose its donors. That helps make the money from principal campaign committees and joint committees merely one part of the puzzle.

“One of the realities in the post-Citizens United world is it’s gotten harder to keep track of total spending, because there are so many different vehicles that have so many different reporting requirements,” said Beckel, referring to a 2010 Supreme Court ruling in Citizens United v. Federal Election Commission that struck down a ban on political spending by corporations.

He noted a recent Wesleyan Media Project report relied on data on advertising spending to shed some light on the battle for Senate control.

That Sept. 8 report says the top five advertisers on broadcast TV over the past month have been Democratic Senate candidates, indicating that those politicians have plenty of cash, while Republican Senate candidates “have been relying on the National Republican Senatorial Committee and One Nation — a group organized as a 501c — to support their campaigns on the air.”

The candidates for the 10 competitive Senate races are now all set, as New Hampshire’s GOP Senate primary took place Tuesday, with retired Army Brig. Gen. Don Bolduc winning. His top opponent, state Senate President Chuck Morse, tweeted early Wednesday that he had conceded to Bolduc.

This is an updated version of a report first published on Sept. 14, 2022.