Sanford’s fatal sin: Crossing Donald Trump

In the end, it wasn’t the Appalachian Trail that brought down Mark Sanford. It was President Donald Trump.

The South Carolina congressman’s stunning defeat in Tuesday’s Republican primary effectively ended the turbulent two-decade career of a political icon who once harbored presidential aspirations. State Rep. Katie Arrington defeated Sanford 50.6 percent to 46.5 percent.

From his time as a congressman in the 1990s, to his eight-year governorship, to his unexpected House comeback that followed, Sanford had long established himself as a figure who cut against the grain — the rare politician who loved to break with his own party. Yet in taking on Trump, his friends and political allies say, he took it a step too far.

His defeat is bound to raise fears among Republicans about the political perils of crossing a president who remains deeply popular with GOP voters. In recent days, Sanford himself had expressed concern that a loss in the primary would discourage what dwindling GOP dissent against the White House remains.

At the heart of Sanford’s downfall was a fundamental miscalculation, those close to him said: that he could go after the Republican president — vigorously, and sometimes in deeply personal ways — and get away with it.