The first rule of opposition research is that you do it on your own candidate. The failure to follow that rule is now causing significant problems for Newt Gingrich and to some extent, Rep. Ron Paul (R-Tex.).

The Wall Street Journal reports:

Newt Gingrich voiced enthusiasm for Mitt Romney’s Massachusetts health-care law when it was passed five years ago, the same plan he has been denouncing over the past few months as he campaigned for the Republican presidential nomination.

“The health bill that Governor Romney signed into law this month has tremendous potential to effect major change in the American health system,” said an April 2006 newsletter published by Mr. Gingrich’s former consulting company, the Center for Health Transformation.

Quin Hillyer, who has been bird-dogging Gingrich effectively, notes that “this is unequivocal, and it is within the past six years, and it shows not a single hesitation about undermining individual liberty. Indeed, Gingrich’s only complaint is a class-warfare-inducing lament: Romney stuck the mandate on lower-middle-income earners, whereas Gingrich only would apply it to middle-middle-income earners. Gee, what a relief! (Not!).”

Moreover, as Hillyer mentions, “Even worse, Gingrich is to the left of Romney on Romney’s own health plan” — since he, unlike Romney, suggested that the Massachusetts plan should be expanded to the whole country.

There’s a third problem, of course: Gingrich — surprise, surprise — hasn’t been candid about his own views on this issue. We come away with the conclusion that at least Romney is honest about his deviations from Republican orthodoxy and is, more or less, sticking by his own plan.

Gingrich needed to stop his slide, and the wave of bad-news stories this week. This isn’t going to help. Anyone who sees Romneycare as a deal-breaker would be hard-pressed to see Gingrich still as a viable option. Coupled with his failure to execute on the ground (his bus tour is making “exactly half of the 44 [stops] he said he would make last week when announcing the tour”), the indication is that his prospects are diminishing.

(It’s not a good sign when you’re the butt of jokes: Mitt Romney, when asked about Gingrich’s failure to get on the Virginia ballot, said: “I think he compared that to . . . Pearl Harbor. I think it’s more like Lucille Ball at the chocolate factory. So, I mean, you know, you gotta get it organized.” Ouch.)

Then there is Ron Paul. The flood of stories about what he knew or should have known was being written under his name in his racist and conspiracy-minded newsletters is not abating. That’s not going to help him grow beyond his core supporters. Does he still win the Iowa caucuses? A party state official who has not endorsed anyone says that if the weather is good (allowing more voters to easily attend) and the newsletter stories keep Paul off-balance, he too could fumble away a win that was easily within his grasp.