16th Assembly District race most expensive in California

It's one of the most expensive political races in California, currently topping $5 million for a single seat in a single district in the California Assembly. But only a fraction of that is being spent directly by the candidate's campaigns rather powerful supporters drawn into the race over the issue of whether transit unions like BART should be allowed to strike.

Four people are running. However, the money being spent in this race is mostly on two candidates who are named Steve Glazer and Tim Sbranti.

Assembly district race heats up

There are three billboards along a stretch of Interstate 680 of one of the candidates. The fine print on the billboards reveals the candidate did not approve the message on it. This is typical of all the messaging addressed to voters in district 16.

For the voters in Assembly District 16, the messages are coming from all directions such as television, radio and in dozens of mailers to their home.

They are mostly negative attacks directed at the two top Democrats in the race. Orinda Vice-Mayor Steve Glazer and Dublin Mayor Tim Sbranti.

"These come from interest groups by and large," Maplight President Daniel Newman said.

Newman tracks campaign spending in California.

"So what we've got here is $5 million spent so far in this race, of which $4 million from so-called independent expenditures, so these are groups that can spend unlimited amounts to influence the direction of the race," Newman said.

The independent spending in the Assembly District 16 race is now $3.96 million, nearly as much as in the State Superintendent of Public Instruction race and three times greater than the District 4 race in Napa.

Laura: "Does the number surprise even you? The amount?"

"Absolutely it does. I mean I'm a teacher from Dublin. I grew up here, you know local mayor, local teacher and you see this kind of money," Sbranti said.

The largest groups supporting Sbranti represent unions and labor, while Glazer has the backing of chambers of commerce and business, largely related to his opposition of future BART and transit strikes.

"And it changed the whole dynamic of the race. It went from just a normal assembly race in California to the high spending contest, because I took on the BART unions and from their point of view, I took on all unions," Glazer said.

Both sides told ABC7 News they have no direct influence over the independent ads and that even the photos used in those campaigns are being pulled off their websites without their authorization.

To learn more about who is spending how much in the various election races, click here.