After a strong first week, Texas Gov. Rick Perry’s presidential campaign has devolved into the “controversy of the week.” First, there was Social Security. Then there was immigration. The debate debacles also unnerved his supporters and potential donors. It's no wonder he quickly sank from his lofty, and it turns out very soft, national poll numbers. Sometimes the first day really is the best one of the campaign.

Now he has two new issues. The Post’s front-page story today is causing understandable waves: “In the early years of his political career, Rick Perry began hosting fellow lawmakers, friends and supporters at his family’s secluded West Texas hunting camp, a place known by the name painted in block letters across a large, flat rock standing upright at its gated entrance. ‘Niggerhead,’ it read.”

The Perry campaign issued a rebuttal taking issue with peripheral matters (e.g., who owned the ranch). On the central issue — did that sign appear when Perry was visiting and taking guests through in the late 1980s and early 1990s — his statement said: “A number of claims made in the story are incorrect, inconsistent and anonymous, including the implication that Rick Perry brought groups to the lease when the word on the rock was still visible.” It’s not an implication, actually. There are direct assertions of fact by eyewitnesses that Perry will need to rebut.

The reaction was somewhat predictable. Right-wing bloggers scoffed that this was trivial. (But if the allegations are true and Perry is lying, isn’t that a pretty big deal?) Complicating his defense, however, was the reaction from the Republican primaries’ newest hot commodity. Herman Cain on ABC was somewhere between blunt and brutal: “My reaction is that is very insensitive. Since Governor Perry has been going there for years to hunt, I think that it shows a lack of sensitivity for a long time of not taking that word off of that rock and renaming the place. It’s just basically a case of insensitivity.” Well, it depends on the timing, I think.

The story is unlikely to vanish (unless New Jersey Gov. Chris Christie gets into the race in the next couple of days, sucking all the oxygen out of the media coverage).

If it were not for the racist rock story line, Perry might be taking more hits for his comments on Mexico. The Dallas Morning News reports:

Gov. Rick Perry suggested Saturday that Mexico’s raging drug war requires deployment of U.S. troops to Mexico — an idea that would offend Mexican sensibilities, though Perry couched the idea only in the context of cooperation.

“It may require our military, in Mexico, working in concert with them, to kill these drug cartels and to keep them off our border and to destroy their networks. It is very important for us to work with them to keep that country from failing,” he said during a stop in Manchester, N.H.

A spokesman attempted to clarify but wasn’t very precise on whether Mexico would have to agree. (“You never know what kind of cooperation you can get when the situation calls for it.”) It’s the sort of off-the-cuff remark that, without full description sounds, perhaps, more radical than it is. I have not received a request for further clarification from the Perry campaign.

Perry supporters may cry that this is much ado about nothing. But it is symptomatic of an ongoing problem for Perry. He has failed to drive his own message and present concrete plans for a Perry presidency. His loose talk, which was fine in Texas, is now a never-ending source of grief. Without a strong positive message of his own, the news vacuum gets filled up with a host of negative portraits. It certainly proves the truism that in politics if you don’t define yourself, others will. For those Republican voters and big donors nervous about his electability, these issues will only exacerbate their fears.

UPDATE, 7:25 P.M.: Sunday evening a Perry campaign spokesman insisted that the governor meant that U.S. troops would be used only in cooperation with Mexico.