Jim Geraghty of National Review Online ponders the Tea Party’s future in the wake of Sarah Palin’s high-profile endorsement of Donald Trump’s presidential bid.

Trump’s an odd figure to win the heart of a public figure once so synonymous with the tea-party movement. He boasts of the influence his money has bought him with politicians, including Charlie Crist, Arlen Specter, and Harry Reid, some of the movement’s biggest enemies. He supported the TARP and auto bailouts and praised socialized medicine. He’s currently touting ethanol subsidies to the rafters in Iowa, and his tax plan would increase the deficit by $10 trillion, according to the Tax Foundation. The day the Tea Party debuted, he praised Obama as “a champion.”

Theory One: Too many of the Tea Party’s leaders left office and moved on.

Quite a few of the political figures most associated with the movement are no longer in public office. Representative Michele Bachmann retired after the 2014 cycle. Former Senator Jim DeMint resigned from the Senate to take over the Heritage Foundation. Former Virginia attorney general Ken Cuccinelli lost his bid for governor in 2013 and now runs the Senate Conservatives Fund. …

… Then there’s Palin. She announced her resignation as governor barely five months after Obama’s inauguration. …

… Theory Two: Too many embarrassing candidates tainted the movement’s reputation. …

… All political movements have their disappointments, but there’s no doubt that by spotlighting passionate amateurs and untested candidates, the Tea Party helped shove some candidates who were simply unelectable into the spotlight. These candidates helped a hostile media paint the movement as extreme and unhinged. …

… Theory Three: The Tea Party actually won, and now represents the true GOP “establishment.”

As Mark Antonio Wright points out, it’s jarring to hear Nikki Haley, Marco Rubio, Paul Ryan, and Trey Gowdy now described as “Establishment” figures. The Tea Party Express, Tea Party Patriots, and Palin all cheered when Mitt Romney picked Ryan as his running mate. How quickly the outsiders become insiders.