Democrat Mike Levin flipped retiring Republican Darrell Issa’s House seat Wednesday, delivering Democrats their first key win in California.

Levin, a former environmental lawyer, defeated Republican Diane Harkey for the open California 49th seat. The win adds to Democratic gains in the House, bringing the tally to 27 seats. Democrats last held control of the chamber from 2006 to 2010.

Democrats targeted Issa's seat early on in their quest for the House majority. Issa, a chief antagonist of former President Barack Obama’s administration, won re-election in 2016 by less than one percentage point.

Democrats made steady registration gains in the northern San Diego County and Orange County district as demographics changed. A local grassroots effort aimed at ousting Issa also helped propel Levin this cycle.

Levin touted his background as an environmental lawyer, putting the issue of climate change front and center in the coastal district, which runs from Dana Point to Solana Beach. Levin ran on a progressive platform, and unlike other Democrats seeking Republican-held seats, he criticized President Trump directly — including a promise on the stump to try to get his tax returns.