Andrew Romanoff, one of the rising stars in the Democratic Party chose to take on Governor Ritter's Democratic U.S. Senate appointee, Michael Bennet, in a Democratic primary to decide who will face off against almost sure to win the Republican nomination Republican Jane Norton.
No one else has materialized to launch a serious more progressive leaning primary challenge to Ritter despite his lack of popularity with the base that has left him with very low poll ratings. Mayor Hickenlooper of Denver, probably the only person who could pull off a statewide Democratic primary win this late in the game (and one of the most popular politicians in the state, even outside Denver), has shown no interest in doing so.
But, is getting Penry out of the race good for Republicans? This is not clear.
[W]e think the risk in this story for McInnis is simpler--he's not the choice of the conservative base, the base's candidate is the one who got punked. By McInnis' well-heeled supporters. Anything that feeds the narrative of rich insiders making the base's primary choice for them is extremely dangerous to McInnis politically, and risks a backlash that money cannot control (see: Dede Scozzafava).
The lack of any serious Republican primaries also denies the GOP a chance to get a serious head start in getting themselves organized in the 2010 election outside the 4th Congressional District while multiple viable Republican challengers will take on moderate Democrat Betsy Markey in the conservative front range district. Romanoff's challenge, in contrast, puts Democrats statewide through the drill of organizing and activating Colorado Democrats for the 2010 primary election, no matter who wins, and this will pay dividends in the 2010 general election.
One of the lessons that the long and drawn out 2008 primary established is that primaries can be good for the political party that engages in them, even when, as in that case, they get heated. And, both Romanoff and Bennet each have a solid history of practicing civility in politics, so the kind of destructive intraparty blood feuds that could damage a political party in a primary race are unlikely to appear in race of the Democratic party nomination to the U.S. Senate in Colorado this election cycle.