The Santa Clara County Democratic Central Committee is on the fast track to endorse its preferred mayoral hopeful, Dave Cortese. But there are growing concerns that the group’s backing will give that candidate the unfair advantage of bypassing campaign finance laws that apply to individual candidates. Campaign staff of Councilman Sam Liccardo, the fundraising frontrunner in the mayor’s race, challenged the DCC in emails to abide by the same rules governing candidates that prevent unlimited spending in an election.