Political horse whisperer Carl Guardino didn’t become one of the valley’s kingmakers with just an uncanny ability to speak in breathless tones normally reserved for kindergarteners. The Silicon Valley Leadership Group CEO has deftly straddled both sides of the Democratic fence for years. In 2012 he allied with San Jose Mayor Chuck Reed to push through Measure B pension reforms before joining now-county supervisor Cindy Chavez’s proletarian revolution to renew a water parcel tax (another “Measure B”). But Guardino’s current push to get a transportation sales tax expedited for the November ballot could prove more difficult than internal Leadership Group polling suggests. In his enthusiasm for mayoral candidate and cycling buddy Sam Liccardo—he organized a PAC that raised around $300 grand—Guardino expended some political capital. Supervisor Dave Cortese, also a candidate for mayor, and Chavez could withhold support for any measure. (Chavez is not known to forgive political slights easily.) That means Guardino may have to convince the Valley Transportation Authority (VTA) to place it on the ballot. If that’s how it shakes out, County Executive Jeff Smith would be thrilled, as the tax would save the county more than a million dollars, and next year’s budget has to be finalized by the end of this month. Guardino, ever a kumbaya chanter in local politics, said it would be “a shame” if his personal politics affected the measure, which would cost taxpayers a ¼-cent sales tax for the next 30 years to improve Caltrain, expressways and also pave the way for BART to downtown San Jose. Noting strong opposition to past transportation measures, Guardino said, “I can’t control the actions of others. If we can’t agree to disagree, I’m not going to let something like that make me lose an ounce of sleep.” A decision to go forward with the measure or hold off until 2016 should come down in the next two weeks.