appreciative of president obama's support but as far as presidential endorsements if we, here's what he has to say. >> i actually don't think it means all that much. i don't believe that the primary voters in colorado care at all who endorsed which candidate. >> reporter: now, keep in mind that president obama has very high ratings with democrats, but the colorado electorate is about a third independent and right now, leaning red. >> shepard: some. analysts call this a race, obama versus the tea party. >> reporter: right. the campaigns are not calling it that but ken buck on the republican side needs to tap into that independent streak here if colorado. because in the past, voters here really just leaned away from anything that appeared to be a little too left or a little too right. they don't like the extremes here and ken buck was carried by the tea party here into the nomination.