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Independent committees that support San Diego’s mayoral hopefuls—but can’t coordinate with them—are emerging as major forces in the special election.

In fact, these committees have already changed the entire big-dollar fundraising picture.

Working Families for a Better San Diego, a political committee established in early September by the San Diego and Imperial Counties Labor Council, is supporting Democrat David Alvarez and has already raised more than half a million dollars to get him elected.

The Labor Council endorsed the first-term councilman, a favorite of unions and other left-leaning interest groups, last month. Since Sept. 20, Working Families has raised $620,000 from just nine contributions. The money has come from either labor unions or unions’ political action committees. The largest contribution was a $250,000 donation from the American Federation of State, County and Municipal Employees, a union representing government workers.

Another pro-Alvarez committee has raised $15,000 from just a single contribution.

This is all possible because unlike candidates, these committees can accept unlimited contributions from individuals, corporations, unions and practically anyone else.

Alvarez isn’t the only candidate to have an independent committee behind him.

Republican Kevin Faulconer has a group called San Diegans to Protect Jobs & the Economy. It hasn’t raised any money yet.

Democrat Nathan Fletcher is supported by Restoring Trust in San Diego. That organization has raised $32,500 in the form of five contributions of between $1,250 and $10,000.

Both the independent pro-Faulconer and pro-Fletcher committees likely will get a lot more money in the coming days and weeks but for now, Alvarez is the biggest beneficiary of independent expenditures.

In direct contributions to his campaign, Alvarez has only $46,000, compared with Fletcher’s $229,400 and Faulconer’s $285,600. But when you add in the independent committees, the pro-Alvarez money in the race jumps to $681,000, placing the 32-year-old councilman’s supporters well above the other two candidates. These committees are not allowed to coordinate their activities with the candidates, and they cannot donate money to candidates’ campaigns.

What are these committees–flush with cash–doing with this money?

So far, Working Families for a Better San Diego is the only committee that’s reported spending money. The group’s reported spending a total of $461,117.50. Among the highlights: $91,000 on polling, more than $150,000 on a field program and $160,000 on television airtime purchases. The committee aired spots during Sunday’s Chargers game and the finale of AMC’s Breaking Bad, among others.

We’re keeping track of big-dollar contributions to these independent committees–along with donations to candidates’ own campaigns–with an interactive chart and searchable database, updated daily. To check it out, click here.

Joe Yerardi is a freelance data journalist for inewsource, where he worked between 2013 and 2016 as an investigative reporter and data specialist. To contact him with questions, tips or corrections, email joe.yerardi@gmail.com.