Michael Bennet, who is trying to hold onto his U.S. Senate seat, has President Barack Obama in his corner. But his challenger in the Democratic primary, former state House Speaker Andrew Romanoff, has a big gun, too: former President Bill Clinton.

Romanoff has “proven himself to be one of the most effective legislative leaders in the entire country, and I think he’s got the best chance to hold the seat in November,” Clinton tells potential voters in automated phone calls (via Politico).

Romanoff will need the help: If the final numbers Public Policy Polling released Monday are any indication, Bennet could take the primary, which culminates when vote tallies are released tonight. Bennet leads Romanoff 49 percent to 43 percent, but nine percent of voters are still undecided, and the margin of error is 4.6 percentage points (via The Hill).

On the Republican side, the race is even tighter. Former Lieutenant Governor Jane Norton is leading prosecutor and Tea Party favorite Ken Buck 45 percent to 43 percent, with 12 percent undecided.

Early voting in the races could be a factor, since most of the state’s counties are conducting a mail-only election, meaning that most voters have already made their decisions. That’s why many candidates have taken their campaigns to El Paso County, home to Colorado Springs, where polls will be open, points out The Gazette.

Meanwhile, in the governor’s race, one man not facing a primary, Mayor John Hickenlooper, a Democrat, has yet to answer questions involving money he received from prominent local businessmen in a land deal involving the sale of tax credits several years ago. A reporter for Face the State went to Hick’s campaign office to ask questions about the matter but was ordered to leave a waiting room.