GWEN IFILL: Voters in Connecticut, Georgia, Minnesota, and Colorado go to the polls tomorrow. The midsummer primary voting is being closely watched, especially in Colorado, where almost nothing is unfolding as expected.
SCOTT MCINNIS,(R-Colo.)Gubernatorial Candidate: My name is Scott.
GWEN IFILL: Deep into the summer, it's primary season in Colorado. But the politics is anything but local.
KEN BUCK,(R-Colo.)Senatorial Candidate: Hi. Ken Buck.
GWEN IFILL: Instead, a pair of statewide races for governor and United States Senate are testing the politics of incumbency and insurgency.
For Democrat Michael Bennet, who was appointed to the Senate only two years ago, the challenge has come from the left.
JANE NORTON, (R-Colo.) Senatorial Candidate: How are you doing there?
GWEN IFILL: And for Jane Norton, the former lieutenant governor who was long considered the favorite to win the Republican Senate nomination, the challenge has come from the right. But it turns out this is not the year where it helps to be considered part of anybody's political establishment.
Independent pollster Floyd Ciruli:
FLOYD CIRULI, Independent Pollster: The election is mostly being framed by this national theme of the anti-establishment, anti-Washington, new-faces insurgencies. In the Republican Party, it's mostly being fueled by the Tea Party movement.
GWEN IFILL: Attorney Ken Buck is challenging Norton.
KEN BUCK: If we continue to pile debt on to our children and grandchildren, we are also morally bankrupt.
GWEN IFILL: In an aggressive ad campaign, Norton has responded by attacking Buck for language he used about her at a campaign stop.
NARRATOR: Here is Ken Buck caught on tape.
WOMAN: Why should we vote for you?
KEN BUCK: Why should you vote for me? Because I do not wear high heels.
NARRATOR: Now Ken Buck wants to go to Washington? He would fit right in.
GWEN IFILL: Most polls now show this primary race too close to call.
(CHEERING AND APPLAUSE)
GWEN IFILL: Colorado Democrats are also deeply split. Although Bennet has the backing of President Obama, he's fighting off a spirited challenge from Andrew Romanoff, the former speaker of the Colorado House.
SEN. MICHAEL BENNET,(D-Colo.): This campaign is not about my job, and that I don't think about my job as my job. This campaign is about the jobs of people all across our state.
GWEN IFILL: Romanoff, who has been endorsed by former President Clinton, has launched an aggressive grassroots campaign.
ANDREW ROMANOFF (D-Colo.),Senatorial Candidate: In the end, I believe we are going to win this race, not just because of who I am, but because of who you are and what you have done for this grassroots, people-powered effort.
GWEN IFILL: Polls show Romanoff and Bennet in a dead heat.
SCOTT MCINNIS: How you doing, young fellow?
In the Republican gubernatorial primary, former Congressman Scott McInnis is facing off against political newcomer Dan Maes, a Colorado businessman. A Tea Party favorite, Maes is tapping into voter anger to use McInnis' Washington experience against him. McInnis also hurt himself when allegations surfaced that he had plagiarized a $300,000 piece of research for a foundation. His handling of the incident caused his fund-raising and poll numbers to plummet.
TOM TANCREDO (R), Former U.S. Congressman: I never would think in a million years -- never would have thought -- that I would be standing here announcing my candidacy for governor of the state of Colorado.
GWEN IFILL: And the political complications don't end there. After McInnis stumbled, former Republican Congressman and presidential candidate Tom Tancredo announced he too is running for governor, but as an independent.
The GOP turmoil has been good news for the Democratic candidate for governor, popular Denver Mayor John Hickenlooper. He managed to escape a primary challenge. But no one is breathing easy.
FLOYD CIRULI: The Democrats cannot open the champagne yet. And the reason is the polls show that John Hickenlooper is not above 50 percent in these polls. That is to say, this is still a pretty good Republican year.
WOMAN: OK. Thank you.
WOMAN: Thank you for voting.
GWEN IFILL: All primary voting, which began two weeks ago, is by mail in Colorado. Some counties are already reporting higher participation than normal.