WASHINGTON — Barack Obama's vote yesterday for a controversial warrantless surveillance bill marked a rare event: the 12th day this year that the Illinois Democrat turned up for a roll call vote in the Senate.

His Republican presidential rival, Arizona Sen. John McCain, has an even worse attendance record: six days. McCain last cast a Senate vote on April 8.

The first election to feature two sitting senators is providing a stark barometer of just how long and distracting presidential campaigns have become. The Senate's roll call votes help illustrate how much time this year's presidential hopefuls have spent on the campaign trail.

OBAMA LEADS IN VOTES

McCain has cast 36 of the Senate's 169 votes this year, according to a USA Today analysis. Obama: 70 votes.

Their truancy began in 2007, long before the primaries and caucuses. McCain's voting participation score, as tabulated by nonpartisan "Congressional Quarterly," dropped from 91 percent in 2006 to 44 percent last year. Obama fell from 99 percent in 2006 to 66 percent last year.