Despite having members in 31 congressional districts that President Trump carried in 2016, House Democrats showed surprising party unity in the December vote to impeach him — but the saga that has gripped Washington could carry a big political risk come November.

On the Senate side, moderate GOP senators essentially face the prospect of political backlash no matter what they do. But on the House side, Republicans already are gearing up to use impeachment as a cudgel against the swing-district Democrats who supported it.

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For instance, Democratic Rep. Matt Cartwright is in Pennsylvania’s 8th Congressional District, which Trump carried by 53-44 percent in 2016. After Cartwright voted for both articles of impeachment, the Cook Political Report moved his seat from “lean Democrat” to a “toss-up.”

Where the Democratic majority could face real challenges is in the dozen districts where Trump won an actual majority of votes in a year when third-party candidates pulled in more than 1 percent of the vote — and about a half-dozen districts where he won by, or nearly by, double digits.

“Democrats hold more seats in Republican areas than vice versa. Impeachment is unpopular in battleground districts,” Michael McAdams, the national press secretary for the National Republican Congressional Committee, told Fox News.

In addition to Cartwright, McAdams said the NRCC is specifically targeting Rep. Anthony Brindisi, in New York’s upstate 22nd Congressional District, as well as Rep. Max Rose of New York’s 11th Congressional District, which is the only traditionally Republican-leaning district that includes part of New York City.

The NRCC is also aiming to defeat Reps. Joe Cunningham, in South Carolina’s 1st Congressional District; Xochitl Liana Torres Small in New Mexico’s 2nd Congressional District and Kendra Horn in Oklahoma’s 5th Congressional District—all districts that Trump carried by close to double digits in 2016, McAdams said.

The Cook Political Report includes all those members in the “Democratic toss-up” category. Moreover, the political analysis group counts 18 Democratic-held seats as toss-ups for 2020, but just five Republican-held seats as toss-ups. These are Reps. Scott Perry in Pennsylvania’s 10th Congressional District and Rodney Davis of Illinois’ 13th Congressional District, as well as open seats in the 22nd and 24th districts of Texas and the 7th district of Georgia.

“After voters enter the booth, they won’t want to support someone who tried to kick Donald Trump out of office,” McAdams said. “For Democrats, impeachment will cost a lot of them their jobs in November 2020.”

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After much speculation as to how many Democrats might buck their leadership, only two – Reps. Collin Peterson of Minnesota and Jeff Van Drew of New Jersey – voted against both articles of impeachment charging Trump with abuse of power and obstruction of Congress.

A third Democrat, Rep. Jared Golden of Maine, voted no on the charge of obstructing Congress, but voted yes on the abuse charge. All three represent districts Trump carried in 2016. Van Drew switched parties to be a Republican after voting against impeachment.

Rep. Tulsi Gabbard, D-Hawaii, doesn’t represent a Trump district, but voted “present” on both articles. She’s a candidate for the Democratic presidential nomination.

In the Senate, impeachment pressure is heavy on moderate Republicans trying to navigate a trial.

Senate Minority Leader Charles Schumer, D-N.Y., has sought floor votes on witnesses that put certain endangered Republicans in an awkward spot – including Sens. Susan Collins of Maine, Cory Gardner of Colorado and Martha McSally of Arizona. After The New York Times reported Sunday on new allegations from former National Security Adviser John Bolton, the pressure rose on such Republicans to consider allowing witnesses like him. All these Republicans are in “toss-up” seats, according to Cook. The only Senate Democrat in a “toss-up” race in 2020 is Sen. Doug Jones of Alabama.

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House Democrats nevertheless have much reason to be optimistic, as the impeachment has boosted fundraising. The Democratic Congressional Campaign Committee outraised the NRCC by a whopping $40 million during 2019, bringing in $125 million – though the Trump campaign and Republican Party as a whole have pulled in staggering sums amid impeachment.

“Our staggering fundraising advantage ensures House Democrats will have the resources to hold Mitch McConnell and Washington Republicans accountable for doing the work of special interests, especially when it hurts hardworking American families,” DCCC Executive Director Lucinda Guinn said in a statement.

The DCCC specifically cited some of those members the GOP plans to target as being the most prolific fundraisers. Rose of New York raised $1.2 million, while Brindisi of New York raised $900,000. Cunningham of South Carolina also raised $900,000.

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Further, Rep. Elissa Slotkin, who in 2018 won a long-held Republican seat in Michigan’s 8th Congressional District, raked in $1.2 million for the year. Rep. Andy Kim, in New Jersey’s 3rd Congressional District, also raised $900,000, according to the DCCC.

One DCCC press release just before the impeachment vote identified several Republicans as “vulnerable” in 2020, citing loyalty to Trump as among the reasons. The DCCC named Reps. Fred Upton of Michigan, Lee Zeldin of New York, Chip Roy of Texas and Brian Fitzpatrick of Pennsylvania. However, the aforementioned Cook Political Report ranked these members as either “lean Republican” or “likely Republican” races.

The DCCC has also attacked newly minted Republican Van Drew of New Jersey, who won as a Democrat in 2018 and switched parties despite having a 90 percent voting record against Trump.