Longshot Republican presidential candidate and all-around iconoclast Rep. Ron Paul (R-Texas) shocked everyone — including his own staff — on Tuesday by announcing that he won't seek a 13th term in Congress next year. After decades on the political fringe, Paul's influence in his party, and outside it, has grown exponentially since his 2008 run for president. This year, he was awarded the chairmanship of the House monetary policy subcommittee, giving him oversight of one of his signature targets, the Federal Reserve. Why retire at the top of his game? Here, four theories:

1. He's passing the torch to a new generation
Paul, 75, probably feels his work in Congress is done and "it's simply time to move on," says Dan Amira at New York. Not only is the GOP now taking his "hard-core libertarian philosophy" seriously, he knows his son, Sen. Rand Paul (R-Ky.), and new Tea Party freshmen will represent his values. He will leave as "arguably the most intellectually influential member of the House of Representatives in a generation," says David Weigel at Slate. And even if he doesn't win the White House, one his disciples, Rep. Michele Bachmann (R-Minn.), just might.

2. He hates his job
Paul's retirement is understandable, says Lew Rockwell at his blog. He hated lots of things about being a congressman — the "twice weekly groping by the TSA" in his Texas-to-D.C. travel, the need to deal with "crooks and creeps in Congress, especially in the rotten Texas delegation." Now he can more effectively use "his moral authority for teaching freedom, peace, and Austrian economics outside of politics." Or maybe, says Jim Newell at Gawker, "being retired and playing golf and stuff is more fun" than "fruitlessly" screaming at Fed Chairman Ben Bernanke.

3. His Congressional district was just eliminated
Although he denies that unfavorable redistricting was a "major factor," Paul clearly wants to avoid "the deadly new district the Republicans have placed him in," says Rockwell. Many observers consider the changes "payback for the congressman's years as a GOP renegade and Tea Party naysayer," says Joe Holley in the Houston Chronicle. The new territory "encompasses areas Paul hasn't represented before, with a greater proportion of black voters," says Patrick Michels in The American Independent, and he loses some key electoral strongholds.

4. Paul is going all-in to win the White House
Maybe we should take Paul at his word when he says he's going to "focus all of my energy winning the presidency," says Paul Constant at The Stranger. Paul has miraculously "broadened his appeal since 2008," and he is polling better than "some 'legitimate' candidates, like Tim Pawlenty," says Michael Crowley at TIME. But retiring won't "improve his (extremely long) presidential odds." Who says he'll stick with the GOP? says Mike Riggs at Reason. Paul staffers wouldn't comment, but there's hope he "will try for a third party run if he doesn't win the Republican primary."