Former U.S. Rep. Tom Tancredo’s string of attacks against U.S. Rep. Mike Coffman raise questions again about what underlying principles motivate Coffman, who’s a Republican from Aurora.

Tancredo now says he doesn’t know if Coffman has “any real set of principles” at all.

But reporters haven’t really explored the question, about how Coffman can go from being, for example, opposed to all abortion, even for rape, to being okay with some abortions. Or from embracing Tancredo as a “hero” to apparently ignoring Tancredo’s criticism of him. Or from saying the Dream Act is a “nightmare” to allegedly supporting it.

It’s time for reporters to help us understand the set of principles that allow Coffman to act this way.

To illustrate the point, I offer this video.

Michael Bennet’s recent TV ad claims that Ken Buck has “even questioned whether Social Security should exist at all.”

The ad then shows a clip of Buck stating, “I don’t know whether it’s constitutional or not. It is certainly a horrible policy.”

In assessing this segment of the Bennet ad this month, most Denver media outlets (e.g., CBS4, 7News , 9News, and a Denver Post editorial ) have said it’s true but misleading. As 9News reported: “It is true that Buck has questioned whether the federal government should be providing a retirement plan instead of the private sector, but it’s false to say he called it a horrible policy.”

9News and other outlets pointed out that Buck wasn’t referring to Social Security when he used the “horrible-policy” line but instead to the practice of borrowing Social Security funds to pay for other federal expenses.

It’s fair to say that Buck’s specific “horrible-policy” line was directed at a narrow aspect of Social Security, and in that sense it’s misleading as used in the ad. But media outlets are being misleading themselves by not analyzing a larger collection of Ken Buck’s statements about Social Security.

Such an analysis, which was done very well by a news reporter at The Post in August and by 9News on its website, reveals the larger point that Buck indeed considers Social Security a really lousy idea, if not a horrible one, even if he doesn’t want to abolish the program. (CBS4, News7, and the Post editorial did not reference the Buck comments below.)

First, there’s this comment by Buck in March:

“But the idea that the federal government should be running healthcare or retirement or any of those programs is fundamentally against what I believe and that is that the private sector runs programs like that far better.”

Then, in an August interview with John King, Buck again said Social Security should be preserved, but he implied that the decision to establish the retirement program was a mistake:

KING: So let’s make clear to anyone, many people just getting to know you across the country, Social Security, 75th anniversary this year. A good policy? Or would you prefer the federal government not get involved in retirement policy?

BUCK: I certainly don’t think it’s what the Founding Fathers intended but we have the policy. We’ve made a promise to our seniors. We need to keep that promise. I think we need to make sure that we are putting Social Security on a sustainable path. It’s absolutely something that the federal government is going to be involved in, in the future. We can make it the best program we can make it.

To get more facts on the table, reporters should ask Ken Buck Bigmedia’s question of the week:

Given that Ken Buck has said “the idea the federal government should be running health care or retirement or any of those programs is fundamentally against what I believe and that is that the private sector runs programs like that far better,” would he have voted for the original act that established Social Security or the one that started Medicare, if he’d been in the Senate at the time?