AP Photo/J. Scott Applewhite, File
The U.S. Capitol at sunset in Washington.

WASHINGTON — Republicans aim to use the House drive toward impeaching President Donald Trump to whittle down Democrats’ majority by dislodging vulnerable incumbents from swing districts loaded with moderate voters.

It could work, especially in Democratic-held districts Trump carried in 2016 with throngs of independent voters who polls shows are closely divided over his removal. Or it could flop, in an era when news zooms by so swiftly that today’s concerns may be eclipsed in 11 months and many people are more focused on pocketbook issues such as health care costs.

“It will be part of the mosaic, but hardly the overriding issue,” GOP pollster Whit Ayres predicted about impeachment’s impact next November. “It will have faded by then and it will also have simply reinforced the preexisting attitudes and made them more intense.”

What’s clear is that for now, Republicans are wielding impeachment mostly as an offensive weapon and Democrats are generally playing defense or changing the subject as 2020 congressional races rev up. House Democrats will be defending their 233-197 majority, with four vacancies. Republicans will try preserving their 53-47 Senate control.

Since late September, Republicans and their allies have spent $8 million on impeachment-related TV ads aimed at House members, according to Advertising Analytics, a nonpartisan firm that examines political spending. That’s triple the sum spent by Democrats and their supporters.

The American Action Network, closely aligned with House GOP leaders, has produced TV and digital ads attacking 30 Democrats, mostly freshmen. Spots also “thank” seven Republicans for opposing impeachment, a tactic often used to pressure lawmakers to stand firm.

In one, the announcer accuses Rep. Joe Cunningham, D-S.C., of abandoning health care and other issues to back impeachment and says, “Tell Congressman Cunningham, ‘Let the voters decide elections.'” The announcer speaks amid images of House Speaker Nancy Pelosi, D-Calif., liberal Rep. Alexandria Ocasio-Cortez, D-N.Y., and Rep. Adam Schiff, D-Calif., who’s led the impeachment inquiry.

GOP groups regularly blast impeachment-themed fundraising emails. Relatively obscure Republicans such as Rep. Elise Stefanik of upstate New York have reaped campaign contribution bonanzas by taking high-profile roles defending Trump.

“This process they’re embarking on is going to cost them their majority next fall,” said Rep. Tom Emmer, R-Minn., who heads his party’s House campaign committee. He said Democrats have “an obsession” with impeachment, adding, “It’s just getting worse for them.”

While Democrats are favored to retain House control, the early blitz of GOP attacks has prompted them to protect their targeted members.

House Majority Forward, an outside group tied to top House Democrats, has spent nearly $2 million defending 14 Democratic incumbents. All but three are freshmen from Trump-won districts.

“Forget the noise. Haley Stevens is focused on Michigan,” said an ad citing the first-term Michigan Democrat.

Pro-impeachment groups have run ads attacking GOP lawmakers for supporting Trump. That included liberal groups MoveOn and Need to Impeach, which put billboard trucks in eight House Republicans’ districts from Nevada to New York that carried signs saying, “Defend democracy. Impeach Trump.”

Stefanik’s step into the spotlight has had decidedly mixed results. Her little-known Democratic opponent, Tedra Cobb, announced she had raised more than $1 million soon after Stefanik stepped into the impeachment spotlight. Cobb has been bolstered by celebrities such as “Star Wars” actor Mark Hamill, who urged his 3.4 million Twitter followers to back Cobb and help Stefanik “spend more time being a #TrumpToady on Fox ‘News.'”

Rep. Cheri Bustos, D-Ill., who leads House Democrats’ campaign committee, said Emmer is “precisely wrong” about her party.