The intensity of the race between State Sen. Scott Wiener and Supervisor Connie Chan to succeed Speaker Emerita Nancy Pelosi went up a notch last week when police officers arrested a suspect for allegedly vandalizing an unofficial mobile installation critical of Chan. The attack-ad-on-wheels resembled the primary season’s “Saikat Mystery Machine,” a guerilla campaign technique tied by the San Francisco Chronicle to political prankster and former City Hall staffer Conor Johnston. On Aug. 7, the cab account posted a photo of the taxi with a banner that read “Connie Chan wants to cancel Outside Lands,” apparently parked near Golden Gate Park. Chan’s spokesperson said the campaign is not aware of any connection between Hoffman and the campaign. “We unequivocally condemn vandalism and any damage to property,” said Chan campaign spokesperson Ian Krager.