Saying that U.S. Rep. Mike Coffman has failed to deliver on President Donald Trump’s agenda, Highlands Ranch Republican Roger Edwards on Wednesday announced he will challenge the fifth-term congressman in the 2018 primary.

A Vietnam veteran who works in logistics, Edwards came out of the gates swinging at Coffman, whom he called a “career politician” that says one thing publicly, while voting another way.

Edwards singled out Coffman’s “lip service” to repealing and replacing Obamacare, while ultimately voting against a GOP plan to undo major pieces of the health care law.

“If Mike Coffman is the Republican candidate in 2018, Coffman will lose to the Democrat,” Edwards said in his campaign announcement.

Coffman since 2008 has held Colorado’s 6th District Congressional seat, fending off well-funded opponents in a district that has long supported Democrats for president, including Hillary Clinton.

But he hasn’t faced a serious primary challenger since he’s been in office, so Edwards’ emergence could add a new dynamic in a district where Coffman has relied on the support of moderates to win.

With 2018 expected to be a tough year for Republican incumbents across the country, both sides are already gearing up for another expensive campaign.

Tyler Sandberg, a Coffman campaign adviser, dismissed Edwards’ assertion that Coffman would lose the general election.

“Mike has withstood literally tens of millions of dollars of lies put on TV by Nancy Pelosi and her political cronies in the last couple years,” Sandberg said in a statement. “He’s a fiscal conservative with a track record of taking on big spenders in both parties, a strong reputation for being his own man, and is more than prepared to tackle the upcoming election, in all phases.”

Edwards is coming at Coffman from the populist right, chastising Coffman for his “grudging support of the president,” and noting that Republicans have made little progress on Trump’s agenda, including tax reform, a border wall between the U.S. and Mexico, and an infrastructure package.

He also challenged Coffman’s conservative credentials, noting that he scored a 55 percent on a conservative voting scorecard put out by Heritage Action for America.

“Fifty-five percent gets you an ‘F’ in school,” Edwards said in a statement. “Don’t the citizens of the 6th Congressional District deserve better than an ‘F’ Congressman?”

Democrats — who have a contested primary of their own with three candidates seeking to unseat Coffman — welcomed Edwards to the race.

“It should come as no surprise that voters across the political spectrum are fed up with Rep. Mike Coffman and Speaker (Paul) Ryan’s do-nothing Congress not working for them,” said Rachel Irwin, a spokeswoman for the Democratic Congressional Campaign Committee. “Coffman’s history of playing both sides of every issue is finally catching up with him and a healthy primary will put his true conservative colors on full display.”

If elected, Edwards pledged to abide by self-imposed term-limits, saying he would retire after two terms in office.