In Colorado, primaries gauge depth of voter unrest

WASHINGTON (Reuters) - Two hard-fought Senate primaries in Colorado on Tuesday pit establishment favorites against rising insurgents in showdowns that could provide the latest gauge of voter unrest before November's elections.

In races considered too close to call, Democratic Senator Michael Bennet and former Republican Lieutenant Governor Jane Norton are waging tough battles for their party's Senate nominations against upstart challengers who have tied them to the status quo.

"The establishment is on the defensive in both parties," veteran Colorado independent pollster Floyd Cirulli said. "Both races look like they could be very close, and they could attract a very high turnout."

The Senate races in Colorado highlight primary voting in four U.S. states on Tuesday. Voters in Connecticut, Georgia and Minnesota also choose candidates to square off in November, when all 435 seats in the House of Representatives, 37 Senate seats and 36 governorships are at stake.

Democrats are struggling to hold their majorities in Congress, with Republicans needing to gain 39 House seats and 10 Senate seats to reclaim control.

In Colorado, Bennet hopes to avoid the fate of fellow Senate veterans, Republican Robert Bennett of Utah and Democrat Arlen Specter of Pennsylvania, who fell in earlier nominating races under an anti-establishment voter tide fueled by anger at Washington and President Barack Obama's agenda.

Bennet, a former Denver schools chief, was a relative unknown in state political circles who was appointed to the Senate last year when Ken Salazar became Interior Secretary.

While portraying himself as an independent voice in Washington he has welcomed the support of Obama, who campaigned in Colorado and filmed television ads on his behalf. Obama won the state by eight percentage points over Republican John McCain in 2008.

"Obama is not hurting Bennet, but he doesn't really seem to be helping him either," Cirulli said.

CLINTON BACKS CHALLENGER

Bennet's challenger, former Colorado House Speaker Andrew Romanoff, has been endorsed by former President Bill Clinton and mounted strong attacks against Bennet from the left.

He aired tough anti-Bennet ads in the final stages of the race that he paid for in part by selling his own house.

"It's an eclectic mix of Democrats behind Romanoff, but they are unified by their disappointment with the establishment in Washington," Cirulli said.

In the Republican Senate race, Norton has struggled to hold off a challenge by former prosecutor Ken Buck, who was endorsed by conservative Tea Party groups and portrays himself as a Washington outsider.

While most establishment Washington groups and politicians backed Norton in the early stages of the race, Buck has been endorsed by another Tea Party favorite, Republican Senator Jim DeMint. Polls show Norton's once huge lead has disappeared.

Norton has scoffed at the outsider claims by the Princeton-educated Buck, a former Justice Department attorney who served as a U.S. and state prosecutor.

Buck drew the ire of some Tea Party backers when he was caught on camera complaining about Tea Party "dumb-asses" who question whether Obama was born in the United States.

In Connecticut, voters also will choose Senate candidates. Democrat Richard Blumenthal awaits the winner of the Republican race between former U.S. Representative Rob Simmons, who recently restarted his suspended campaign, and former wrestling executive Linda McMahon.

A new Quinnipiac poll on Tuesday showed the Democratic race for the nomination for governor was a dead heat, with businessman Ned Lamont at 45 percent and former Stamford Mayor Dan Malloy at 42 percent.

A Lamont victory would be a political comeback for the candidate who knocked off Joe Lieberman in the 2006 Democratic Senate primary and then lost the general election to Lieberman, who ran as an independent.