Democrat Harder upsets California GOP US Rep. Denham

First-time candidate 32-year-old venture capitalist Josh Harder defeated four-term Republican U.S. Rep. Jeff Denham in California's farm belt, giving Democrats their fourth pickup of a GOP House seat in California.

Harder had anchored his campaign to Denham's vote against the Affordable Care Act, while arguing that he would push for universal health care in Congress. He also argued that Denham and other Washington Republicans ignored poverty and health care in the agricultural 10th District in California's Central Valley.

Harder said in a statement "Washington is broken because our leaders have put party over country. I pledge that I will always put this community before anything in Washington." As ballot-counting continued, Democrats gained ground in two undecided House races in  Orange County raising the possibility of a Democratic sweep of four closely contested congressional races in the one-time Republican stronghold.

In the 45th District in Orange County, Democrat Katie Porter jumped into a 261-vote lead over Republican Rep. Mimi Walters, after trailing the incumbent since Election Day.

And in the 39th District, anchored in Orange County, Democrat Gil Cisneros tightened the gap with Republican Young Kim.

Earlier, Democrats claimed the seats of Republican Reps. Dana Rohrabacher in the county's 48th District and retiring Darrell Issa in the 49th District, which cuts through the southern end of the county.