Former Republican vice presidential candidate Sarah Palin endorsed Republican presidential candidate Donald Trump during a campaign rally in Ames, Iowa. (Reuters)

Update: Trump has released a statement announcing Palin's endorsement: “I am greatly honored to receive Sarah’s endorsement. She is a friend, and a high quality person whom I have great respect for. I am proud to have her support.”

Late Monday evening, during the waning hours of a three-day weekend, a subset of America's political watchers turned its attention to a small twin-engine charter jet that was passing over the emptiness of the Canadian West.


Flight TWY123 left Anchorage at about noon Alaska time and landed in Des Moines at around 8 p.m. Central. It appears to have been spotted by posters at the conservative site Free Republic before anyone else. And, for that audience, it suggested one thing: Sarah Palin was on her way to 2016.

This wasn't totally out of the blue. On Sunday, Donald Trump teased an event in Iowa on his Facebook page.

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A "special guest"! A charter flight from Anchorage! Could it be?

Trump's event is in Ames, about 45 minutes north of Des Moines, meaning that a flight in the day prior and a quick jaunt to the venue sounds about right. Palin and Trump have done a bit of a political minuet, so far, this year. The two appeared at an anti-Iran-deal rally at the Capitol (along with Ted Cruz and others). Trump suggested he might tap Palin for his Cabinet (she'd like energy secretary) and Palin interviewed him (sort of) for One America News.

Ted Cruz said on the campaign trail on Jan. 19 that "Sarah Palin is fantastic," despite her endorsement on Republican presidential front-runner Donald Trump. (Dalton Bennett/The Washington Post)

Steve Deace, host of a prominent conservative radio show in Iowa, tweeted on Monday night that "pretty much everybody I know" thinks a Palin endorsement is imminent.

So let's do some pros and cons on this theory.

Pros

• Trump and Palin have similar politics. FiveThirtyEight's Nate Silver picked up this graphic from On The Issues to demonstrate where Trump and Palin fall on the political map. It speaks for itself.

...And styles. Palin's 2008 vice presidential campaign was something of a preview of Trump in 2016. Tons of personality, a relative disinterest in the nuance of policy, a reliance on the public's fascination with them.

• How could Palin not weigh in? Palin backed Cruz during his initial bid for the Senate, during the last days of the prominence of the tea party movement. There's some overlap between Palin and Cruz politically that might still resonate for the former Alaska governor.

But Palin clearly relishes being in the political spotlight, from which she's been absent for a while. Backing someone for 2016 would certainly give her a moment -- and who better than Trump to make sure it's seen as widely as possible? Every rally Trump holds is televised; he's a phenomenon beyond what she could have envisioned in 2008.

• Palin is likely still popular with most Republicans. The last time Gallup asked about Sarah Palin was in July 2013. At that point, only 35 percent of Americans viewed her favorably -- but 61 percent of Republicans did. Her numbers are probably still fairly high with Republicans.

• Palin likely bolsters Trump on the far right. Cruz picked up a lot of support from the most conservative Republicans after Ben Carson collapsed. Palin can probably help Trump eat into Cruz's advantage there, given her long-standing support among that group.

Cons

• A Palin endorsement might not help much. Deace, who backs Cruz, thinks that a "flashy" endorsement wouldn't help Trump much in the caucus state. This is more of an argument that the political play won't work than that Palin won't show up, mind you.)

A 2012 poll from The Post and Pew Research found that a Palin endorsement that year wouldn't have made a difference for 60 percent of voters -- including 61 percent of Republicans. But it's hard to believe that for the audience Trump wants to target -- hard-right Iowans -- Palin's endorsement would hurt him any.

Republicans may like her more when she's out of politics. In a CBS News poll in January 2015, 59 percent of Republicans said that they wouldn't want her to run for president in 2016. She didn't, obviously, but it does prompt some question of whether or not people would react well to her jumping in at this point?

Maybe? Maybe not. It's hard to come up with cons on this. Trump and Palin have had a nice symbiotic relationship going for a while now, and this is a natural next step.

Perhaps the best "con" is this one.

• That plane from Anchorage? It left Des Moines for Tulsa within half an hour. Suggesting, perhaps, that it only landed in Des Moines to refuel. In which case it was just some random person from Anchorage headed to Tulsa, maybe on business for an oil company.

Update: As noted on Twitter, Trump has an appearance in Tulsa on Wednesday. Perhaps it's there to shuttle Palin back home, after she travels with him to Oklahoma?

Update, post-Palin being announced: This appears to have been correct!

If the plane wasn't carrying Palin, though, Trump's special guest just had the worst possible introduction: A lot of build-up in the expectation of someone a lot more exciting.