For two generations after the Civil War, the Republican Party routinely won elections by running against the Confederacy and Jeff Davis (with a healthy dose of anti-Catholicism thrown in for good measure). One particularly inventive GOP candidate even took to carrying the alleged shirt of one of his martyred comrades around to his stump speeches. At the emotional climax of his rant against the treasonous Democrats and their papish ways, he would thrust the soiled, ragged garment over his head for the audience to see — thus the phrase "waiving the bloody shirt."
It was a powerful bit of theatre. But as the veterans of the Grand Army of the Republic aged and died and the wounds left by the war either healed or scarred over, the message gradually lost its kick — even among the GOP faithful.
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[I]f we’re lucky, very lucky, what happened then may happen again, making this election the last (and hopefully futile) wave for the Vietnam War’s version of the bloody flag.
The Bloody Shirt