Democrat T.J. Cox overtook incumbent Republican Rep. David Valadao in California’s 21st congressional district in late ballot counts Monday — nearly three weeks after Election Day.

Valadao had a comfortable lead of 6.4% on Election Day. But California has extremely lenient rules about mail-in ballots, allowing ballots to be counted as long as they are postmarked by midnight on Election Day and received within the three days following.

As of Monday evening, Cox now leads Valadao by 0.4%, or 436 votes out of nearly 111,000 counted so far in the rural, heavily Hispanic district in California’s Central Valley.

Cox had severe weaknesses as a candidate, including the fact that he had a “primary residence” in Bethesda, Maryland. Valadao crushed him in the primary race by nearly two-to-one.

But the Democrats’ turnout machine proved too strong for Republicans across the state — including, apparently, Valadao. There is little hope that the remaining ballots to be counted will push him back into the lead. And at least one news outlet that called the race for him on Election Day had already retracted its call.

Valadao’s apparently imminent defeat means that Democrats will have won seven out of the seven districts they targeted in 2018 — all of them districts in which Hillary Clinton won more votes than Donald Trump even though Republicans were re-elected to U.S. House seats in each.

Curiously, Republican turnout was stronger than Democratic turnout in the June 5th primary in all but six of those districts. But Democrats ramped up their efforts — and their spending — to overtake the GOP across the state.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. He is also the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.