WASHINGTON — President Trump is raising record amounts of cash for his 2020 re-election. But that fundraising might isn’t spilling over to the most vulnerable Republicans fighting to hold onto their seats in a narrowly divided Senate.

During the third quarter, former astronaut Mark Kelly took in $2.5 million more than Republican Sen. Martha McSally in Arizona. In Maine, state House Speaker Sara Gideon bested longtime Republican Sen. Susan Collins by over $1 million for the quarter, although Collins still had more cash on hand. And in Colorado, Cory Gardner, who led Senate Republicans’ campaign arm in 2018, barely outraised former Gov. John Hickenlooper, who had been in the race just five weeks before the quarter ended.

The trouble for Republicans extends to states where they’re supposed to be on firmer ground. Iowa Sen. Joni Ernst didn’t crack $1 million and was outraised by the leading Democrat. North Carolina Sen. Thom Tillis narrowly outraised Democrat Cal Cunningham but is also facing a primary challenge from the right that has forced him to spend millions in early TV and radio ads.

The lagging numbers suggest that much of the enthusiasm among the Republican base is focused on Trump and doesn’t necessarily translate to Republicans running for other offices. Democrats, meanwhile, are paying close attention to races across the board, including the House, Senate and presidency, fueling them with small-dollar donations that Republicans have struggled to counter.

Fundraising prowess isn’t always an indicator of who will actually win on Election Day. But the dynamic could complicate the Republican Party’s effort to maintain its 53-47 grip on the Senate.

This should serve as a “real wakeup call,” said Scott Reed, a senior political strategist for the U.S. Chamber of Commerce, a group that has long been allied with Senate Republicans. The “ongoing Trump drama” over impeachment and other issues “drowns out all the political news back home every single night,” making it difficult for Republican candidates to get their message out, Reed said.

But the challenges facing Republicans have mounted in recent weeks as the Democratic-controlled House pursues an impeachment inquiry. Instead of focusing on their own records, Republicans seeking re-election have often been barraged with uncomfortable questions about Trump’s conduct. The pressure will only grow if the Senate holds an impeachment trial, forcing these Republicans to decide whether Trump should be removed from office.

“Republicans are going to struggle with fundraising and messaging if the only thing they can talk about is President Trump,” said Jonathan Kott, who was a senior adviser to Sen. Joe Manchin, a West Virginia Democrat, during his successful 2018 re-election bid. “What we found is no matter how popular the president is, you have to stand up to him when it’s good for your state. Democratic senators are finding a way to do that. Republican senators aren’t.”

Democrats also have a small-dollar cash advantage.

Despite an organized push, Republicans have yet to develop an online fundraising behemoth rivaling ActBlue, the Democrats’ donation platform, which enables donors across the country to direct a contribution of $1, $5 or any amount up to $2,800 with a few taps on a smartphone.

“Democrats over the last several years have formulated a culture among the activist class where every time they are motivated by content or a candidate they contribute five bucks,” said Josh Holmes, an adviser to Senate Majority Leader Mitch McConnell, who is running for re-election in Kentucky and was outraised almost 5-to-1 last quarter even though the state isn’t considered a battleground. “Republicans have made strides, but we still have a long way to go.”

Still, there are bright spots for the Republican Party. In order to regain control of the Senate, Democrats might have to win in states that have traditionally sided with Republicans over the past two decades, such as Arizona and Georgia.

And some Republican candidates are successfully putting Democrats on defense. Michigan candidate John James, who came up short in his bid last year to oust Sen. Debbie Stabenow, is now beating Democratic incumbent Gary Peters in the money game. The African-American, pro-Trump candidate raised $3 million, while Peters took in $2.4 million over the past three months, records show.

In Georgia, where there will be two Senate seats on the ballot because of the retirement of Sen. Johnny Isakson, Democrats are still sorting out who all will run. Jon Ossoff was the top-raising Democrat in the contest to take on Republican incumbent David Perdue. But of the $1.3 million he took in, more than $500,000 was left over from his failed 2017 bid for a suburban Atlanta House seat. Perdue, meanwhile, raised about $2.5 million.

While Republicans acknowledge they face an unfavorable political environment, it’s also early in the cycle.

In 2018, Democrats appeared to be making strides in Senate contests as the election neared, but the party’s handling of a sexual misconduct allegation leveled against now-Supreme Court Justice Brett Kavanaugh galvanized the Republican base and helped them turn the tide. Kavanaugh denies the allegation. If Democrats were to mishandle the impeachment inquiry of Trump, it could deliver a similar jolt.

“Democrats have found fundraising success pretty regularly during the last several years,” said Jesse Hunt, spokesman for the Republican Senatorial Campaign Committee. “In many cases, that’s not manifested itself into electoral victories.”