Understand that Colorado might end up deciding which party controls the Senate next year. Right now, in the RCP poll average, Udall and Gardner are separated by less than a point.

Oh well.

U.S. Sen. John McCain plans to barnstorm the country on behalf of Republican Senate candidates in states such as Kansas, Iowa, North Carolina, New Hampshire and Oregon.

However, McCain, R-Ariz., told The Arizona Republic that he intends to sit out the heated Senate battle in Colorado, where incumbent U.S. Sen. Mark Udall, D-Colo, is in peril. McCain is a longtime friend of the Udall family and considers Udall’s father, the late longtime U.S. Rep. Morris Udall, D-Ariz., a congressional mentor.

Asked if he was avoiding Colorado because of his long association with Mark Udall, McCain answered, “and his father, yes.”…

McCain’s 2002 memoir “Worth the Fighting For” includes a chapter titled “Mo” in which McCain detailed the kindness and generosity Udall showed him while he was a junior Interior committee member who at a time “barely understood the difference between the U.S. Forest Service and the Bureau of Land Management and couldn’t tell a copper mine from a cotton farm.”

Mo Udall was an Arizona Democrat so far to the left that he ended up running for president in 1976 on grounds that Jimmy Carter wasn’t liberal enough. His friendship with McCain was the real deal, though: Not only was Udall gracious and welcoming to the newbie Republican congressman, McCain repaid the kindness later by visiting Udall regularly for years after the latter was hospitalized due to Parkinson’s, even when Udall couldn’t recognize his visitors. It’d be crass given their history to expect McCain to be an attack dog against Udall’s son — but no one’s asking him to do that. Why couldn’t he hold an event with Gardner and say that while he has the warmest personal regards for the Udall family, elections are ultimately about choosing the best policies for the country? Wasn’t that his campaign motto in 2008, in fact — “Country First”?

But maybe it’s for the best. We’re on the brink of having both major parties choose their next nominee largely based on that person’s blood relation to an ex-president. If we can choose the leader of the free world based on blood, we might as well choose our legislators based on friendship.

I’ve got to challenge one point I’m seeing on Twitter in response to the McCain news, though. Some righties are laughing and saying, “Good! Having McCain stay away can only help Gardner.” Er, why? I know he’s conservatives’ least favorite Republican, but so what? Tea partiers will be out in force for Gardner no matter what, as a way of flipping the bird to Obama. A campaign event with McCain won’t do anything to change that. Meanwhile, I’m sure there are some low-information Republican voters in Colorado — the kind who, on a good day, might be able to name three big-name GOP politicians besides Ronald Reagan and the two George Bushes — who might perk up if McCain came to town. That’s not because they have any special love for Maverick, it’s because they recognize his name as a former party nominee, and his name recognition might translate into extra name recognition for Gardner. National polling on McCain is scarce these days but as of last June (months after he’d joined the Senate’s amnesty Gang of Eight) he stood at a healthy 52/39. His numbers were much worse than that back home in Arizona earlier this year, but that’s partly because Arizonans, especially conservative Arizonans, have an incentive to follow him closely in the Senate. Coloradans don’t. To many of the latter, I’d bet, McCain’s nothing more nor less than the guy we should have elected six years ago to spare us the disaster of Hopenchange. Think Gardner would benefit from a photo op with that guy?

Exit quotation: “McCain said he still has not made up his mind about running for re-election in 2016, but told The Republic, ‘I’m feeling inclined.'”