When the dust cleared this afternoon after thousands of votes were counted in San Mateo County, Santa Clara County Supervisor Joe Simitian was back in the lead – by 44 votes – in his nerve wracking seesaw battle with Assemblymember Evan Low for a runoff spot in the 16th congressional district.

The latest vote totals – as of 4:20pm in Santa Clara County and 4:30pm in San Mateo County – showed Simitian back in the lead over Low after losing ground all week.

One day earlier, with an estimated 5,000 unprocessed 16th District ballots in San Mateo County, the former state legislator and Palo Alto council member trailed Low by 63 votes.

About 20% of 16th District voters are in San Mateo County, where Simitian has more support than Low, who has more support in Santa Clara County.

Former San Jose Mayor Sam Liccardo has steadily widened his lead over Low, Simitian and 8 others since polls closed March 5. As of this afternoon, Liccardo had the support of 38,361 voters, just over 21% of votes cast in the 16th District.

Wednesday's ballot counts in Santa Clara and San Mateo counties had resulted in a 221-turnaround for Low, after Simitian had led throughout the first week since the March 5 Primary Election by as many as 1,500 votes.

Simitians’s total from both counties, as of this afternoon, was 30,163. Low’s total was 30,119.

The coveted 16th District seat represents about half of the City of San Jose, its western suburbs and the heart of Silicon Valley. The district includes sections of southern San Mateo County and northern and western Santa Clara counties.

The vote totals are incomplete, partial and unofficial returns from the Santa Clara County Registrar of Voters , the San Mateo County Elections Office  and the California Secretary of State.

The 16th District seat was left without an incumbent with the November announcement by Rep. Anna Eshoo that she would not seek re-election after 30 years in the House. Eshoo later endorsed Simitian as her successor.

In the “top-two" open primary, voters of any or no party affiliation could vote for any candidate, and the top two vote-getters advance to runoff election in November.

San Mateo County election officials today reported 450 “unprocessed conditional ballots.” Santa Clara election officials today reported 1,500 “unprocessed conditional voter registration ballots,” another 100 unprocessed provisional ballots and 1,300 “challenged ballots (pending voter signatures).

Election officials in both counties said their next reports would be Monday.

Liccardo, 53, served two terms as San Jose mayor and two-terms as a council member following a stint as a prosecutor in the county District Attorney’s Office. The Georgetown and Harvard Law School grad grew up in Saratoga, and in San Jose near his grandfather’s grocery store. Considered a moderate with strong ties to Silicon Valley tech and real estate firms, he led the city during its growth as a tech center, championed a high-speed rail link and BART extension into San Jose and gained national recognition for the city’s attempt to require gun owners to have liability insurance.

Low, 40, an openly gay progressive with strong organized labor support, has served in the Assembly since his first election in 2014. He is a former mayor and council member in Campbell, and is considered a rising next-generation star in the Democratic Party. He also is chair of the California Asian American & Pacific Islander Legislative Caucus and a Member of the California Legislative LGBTQ Caucus.

Simitian, 71, is in the final year of his third term as a Santa Clara County supervisor. The former Palo Alto council member served in the California legislature as an Assembly member and state senator. He led efforts in the county and state to build affordable housing, increase environmental protections and boost mental health services. He led early with endorsements from many local elected officials – highlighted by a cherished endorsement from Eshoo –, and was considered a moderate Democrat.