In Colorado, Democrats hope Michael Bennet can hold onto his Senate seat. It was a split decision Tuesday night, not between Republicans and Democrats but between insiders and outsiders, CBS News Correspondent Jeff Greenfield reports.
Special Section: Campaign 2010
Democrats gave a comfortable primary victory to Bennet, who survived a strong challenge from former statehouse Speaker Andrew Romanoff.
They also spared President Obama - who campaigned hard for Bennett - the embarrassment of explaining why Colorado Democrats had rejected his candidate.
It was a different story on the Republican side. District Attorney Ken Buck, the Tea Party favorite, won a close race against former Lt. Gov. Jane Norton, the choice of the Republican establishment. Buck was aided by $2 million worth of ads and mailers from the Virginia-based Americans for Job Security.
In the fall, both Buck and Bennet are likely to stress their independence for good political reasons, says pollster Floyd Ceruli.
"Being an 'in' today in the political system is not where you want to be," he said.
Democrats have done well in Colorado in recent years, but with GOP gains likely elsewhere, they can ill afford to lose there if they hope to hold the Senate in November.
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Interactive Map: CBS News Election 2010 Race Ratings