Democratic performance in Republican-leaning districts will prove crucial in determining control of the House in November. Lamb's win in an area President Donald Trump won by about 20 percentage points gave the minority party in Congress fresh optimism about its ability to win the 24 seats needed to control the House. Doing so would require beating Republican incumbents in districts won in 2016 by not only Democrat Hillary Clinton and but also some carried by Trump.
After Lamb's victory, Republicans shrugged him off as a unique candidate whom Democrats will struggle to replicate. On the GOP side, lawmakers and strategists argue Democrats will have trouble finding other moderate military veterans who do not face a serious primary challenge. Primary elections can pull candidates toward their party's extremes and make them less appealing in a general election.
"This is something that you're not going to see repeated, because they didn't have a primary. They were able to pick a candidate who could run as a conservative, who ran against the minority leader, who ran on a conservative agenda," House Speaker Paul Ryan said earlier this month after Lamb's win.
Lamb did not run as a "conservative," as he opposed major Ryan initiatives such as the GOP tax cuts and Obamacare repeal, but he certainly took centrist stances on some issues.
"House Republicans won't say it publicly but they woke up after the special election terrified by the fact that we have a huge amount of Democratic candidates who uniquely fit their districts and have deep records of service," said the DCCC's Law. "But that's not all that keeps them up at night – Republicans know that their stale playbook backfired, particularly on taxes, and now they're stuck without a single popular accomplishment to campaign on."
Along with Kelly, the House Democrats' campaign arm has put its weight behind several candidates challenging Republican incumbents who share at least some qualities with Lamb. Of the 33 challengers getting the DCCC's organizational and fundraising support as part of its "red to blue" effort, at least a dozen have some military or national security experience.
Democrats often try to run candidates with military or national security backgrounds to counter a GOP narrative that the party is weak on defense or crime, said Elaine Kamarck, a senior fellow at the Brookings Institution and a Democratic National Committee member. That experience is "particularly valuable" in swing districts where Democrats will need voters to cross ideological lines, she said.
Of course, many of those candidates will not mirror Lamb on issues such as abortion or gun rights. The districts they hope to represent have varying local priorities and ideological leanings that can lead to different policy platforms from Democrats. For instance, Lamb and Kelly have both courted steelworkers' unions, which have a presence in their districts but not as big of a foothold in other Republican-held areas.