Probably not fatal to the GOP’s hopes of retaking this seat, but not helpful either.

Per Becket Adams, since when do tea partiers describe rich people as “the one percent”?

[Palin] is slated to appear at a Saturday event organized around [Rob] Maness’s “#OneofUs” campaign, a campaign intended to frame the candidate as an average Louisianan in contrast to the GOP front-runner in the race, Rep. Bill Cassidy, and Sen. Mary Landrieu (D-La.), both of whom Maness has characterized as out-of-touch Washington elites.

“If you could sum up this campaign, it’s two of them vs. one of us,” a source familiar with the event told The Hill.

“Mary Landrieu illegally uses taxpayer dollars to pay for charter planes. Bill Cassidy is hosting Mitt Romney at a white-linen fundraising event for the 1 percent. Former Republican vice presidential nominee and Gov. Sarah Palin will be joining Rob Maness at an event here in Louisiana at a local restaurant with a great story serving some gator.”

As I say, not helpful but probably not fatal. This would be bad, bad news if Louisiana was holding a traditional general election in November, where the candidate with the most votes becomes senator. Maness is polling at around seven to 10 percent; Cassidy is in the mid-40s in most surveys. In a traditional election, you’d be looking at the possibility of a 45/40/15 Mary Landrieu win, with Cassidy and Maness splitting the conservative majority. But that’s not how things work in Louisiana: They hold a ‘jungle primary” in November in lieu of a general election, with the two top vote-getters advancing to a runoff in December unless one of them somehow pulls a clear majority. No one thinks Landrieu is getting 51 percent on the first vote, so even if Palin drives a chunk of tea partiers away from Cassidy and towards Maness, Cassidy’s still going to be in the runoff with Landrieu. Palin might even endorse him at that point in the name of party unity, just as she has Pat Roberts in Kansas.

The question is, could Cassidy possibly reach 51 percent on the first ballot and avoid the runoff with Landrieu? He’d be favored to win, but anything could before December. Democrats will throw everything they’ve got into helping reelect Landrieu, especially if the results on election night in November produce a very narrow GOP Senate majority. For Republicans, it’s much better to win this race ASAP. Maness’s candidacy and Palin’s endorsement of it makes that less likely — but how much less? Noah and I were chatting about it this morning and he flagged these recent numbers from Fox News:

Even if you move all of Maness’s voters into Cassidy’s column, he’s still nearly 10 points away from an outright majority. (The same poll showed him up 51/38 in a head to head race with Landrieu a la the runoff.) If Fox’s data is accurate then Palin’s endorsement of Maness doesn’t much matter: Realistically, it’s already unlikely that Cassidy’s going to get 51 percent during the “jungle primary.” On the other hand, a poll taken earlier this month by Rasmussen showed Cassidy with 44 percent, Landrieu with 41, and “other” with nine — which would put Cassidy within striking distance of winning the election on the first ballot. To make it happen, he needs big-name tea partiers telling Louisianans to forget Maness and opt for the Republican with the chance to win. Palin’s apparently ready to tell them the opposite.

Why would she do it given that Maness has zero chance? The conventional wisdom on social media is that she’s trying to placate conservatives who might otherwise object to her stumping for Pat Roberts. It’s probably the most efficient way for her to behave if she wants to (a) get involved in the midterms down the stretch but also (b) guarantee a Republican Senate. Roberts is the guy who’s in deep trouble, not Cassidy; a conservative campaign against him led by Palin or some other tea-party star really could wreck what little chance he has left of retaining his seat. So she’s going to bat for him but also for the longshot Maness to reassure grassroots righties that, per Maness’s campaign theme, she’s “one of us.” And as I say, it may well be that she ends up endorsing Cassidy anyway before the runoff once Maness is out of the picture.

Exit question: Why would Palin of all people feel the need to prove her grassroots credentials at this point by endorsing a longshot? She endorsed Chris McDaniel against Thad Cochran during a far more competitive, far more important primary where there’s almost no chance of the seat turning Democratic. She’s got nothing to prove.