The Republican base is fired up by impeachment: It’s driving fundraising to pro-Trump groups, which pump that money back into ads to get the base even more fired up.

Why it matters: The cycle keeps spinning, generating more and more heat. That’s why they’re locked in, unified, defending Trump.

Driving the news: The non-profit arm of pro-Trump super PAC America First Action is dropping $2.26 million on ads beginning today, targeting 27 Democratic House members the group sees as most politically vulnerable in the impeachment fight.

Pro-Trump groups are flooding the airwaves ahead of this month's expected House vote on articles of impeachment — spending millions to pressure Democrats in swing districts to vote no.

"The goal is to make the impeachment vote as hard as possible for them," America First Policies spokeswoman Kelly Sadler tells Axios.

The ads are timed to pick up after a run of similar anti-impeachment ads from another pro-Trump group, American Action Network.

Starting next week, both groups will ramp up at the same time for "a full court press," Sadler said.

The Republican National Committee and Trump campaign will run their own ads calling Democrats' impeachment effort a "sham," sources familiar with their plans tell Axios.

Details: The 30-second America First spots, which will appear on Facebook, via text, in newspapers and on TV over the next two weeks, are nearly identical to the ads the group spent $1 million on in October.

The narrator in the ads says that “the radical left will stop at nothing” and calls on viewers to "end the witch hunt, oppose impeachment, put America first" — against a backdrop of images of House Judiciary Committee Chairman Jerry Nadler, Intel Chairman Adam Schiff and Speaker Nancy Pelosi.

Each ad is personalized to target individual lawmakers — all of whom are in districts Trump won in 2016.

Full list of targeted lawmakers: Anthony Brindisi (NY-22), Kendra Horn (OK-05), Joe Cunningham (SC-01), Jared Golden (ME-02), Xochitl Torres Small (NM-02), Matt Cartwright (PA-08), Antonio Delgado (NY-19), Elissa Slotkin (MI-08), Ben McAdams (UT-04), Abigail Spanberger (VA-07), Andy Kim (NJ-03), Lauren Underwood (IL-14), Abby Finkenauer (IA-01), Cindy Axne (IA-03), Elaine Luria (VA-02), Conor Lamb (PA-17), Cheri Bustos (IL-17), Ron Kind (WI-03), Haley Stevens (MI-11), Dave Loebsack (IA-02), Sean Patrick Maloney (NY-18), Chris Pappas (NH-01), Lucy McBath (GA-06), Angie Craig (MN-02), Tom O’Halleran (AZ-01), Josh Gottheimer (NJ-05), Mikie Sherrill (NJ-11)

Watch one of the ads here.

Editor’s note: This story has been corrected to show that 27 Democratic lawmakers are being targeted, not 28.