Very shortly, I think we’ll see in Iowa the Republican candidates focus on Newt Gingrich’s lobbying and other liabilities. As Craig Robinson of the Iowa Republican put it, “For [the lobbying] to become an issue that would affect his campaign, I think one of his opponents would have to shape the argument by making it easy for voters to understand. That means the criticism has to be able to be condensed into a 30- or 60-second radio or TV ad, not a 1,500-word article in a newspaper.” If not an ad, then at least in the debates. Candidates who need to finish at or near the top of the pack have very little to lose by going after Gingrich’s weak spots with social conservatives and Tea Partyers.

It may be especially tempting to raise the lobbying issue in a debate. Gingrich doesn’t react well to criticism, and his condescending and often huffy routine with the press doesn’t play so well against his opponents. An Iowa state GOP official who is neutral in the race e-mailed me, “It is going to be current revelations . . . that will truly do him in because he does not have the message discipline required to survive this process.”

You can already hear the ammo being loaded. Texas Gov. Rick Perry, who’s had his own gaffes (albeit minor ones this week) is letting it be known that he is coming after the “insiders,” a jab at both Mitt Romney and Newt Gingrich. Perry promises a “harsh and strong”contrast, which may be a little hard, given that he’s been in office much longer than Gingrich was speaker or Romney was Massachusetts governor.

Gingrich faces a situation in which multiple candidates will come after him, in essence badgering him to acknowledge his ideological heresies and his years of lobbying, which he continues to deny. (We’re going to hear a lot of “Yes, as Michele was saying . . . . and “But Newt, I don’t think you answered Rick’s question about how many millions you made from health-care companies.”) It is particularly treacherous for him since he has convinced himself of something (e.g., not a lobbyist, against big government) that most people looking at his record just won’t buy.

Speaking of which, where is the accounting of all his lobbying, er . . . consulting activities, that he promised when the Freddie Mac story broke?

It may be not the track record that brings him down but his reaction to it. (We saw Perry’s “heartless” comment do more damage than simply his stance on in-state tuition breaks for children of illegal immigrants.) Remember that Gingrich got points in prior debates for seeming to be above the fray and assuming the role of elder statesman. But what if he turns into a bully, a common reaction of his to the media’s questions? (Although not to her face, Gingrich lashed out at Bachmann, calling her “factually challenged” like one of his dimmer students. If he does that onstage, listen for the boos.)

As Dana Milbank put it this week, “gratuitous nastiness, to allies and especially to his own staff” and “being smart but not thoughtful” can get a pol in hot water. Now he was talking about Rep. Barney Frank (D-Mass.), but many of the same criticisms and the telltale snarly response to tough questions are problematic for Gingrich.

It has always been the case in Gingrich’s career that, just as he gets to the top, he undermines himself by hubris, loose talk and shady dealings. His opponents who want to make sure that pattern repeats itself will do everything they can to pressure him; For some competing in Iowa, that may be the difference between going home and staying in the race.