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The hottest new trend for long-shot campaigns is VP short lists.

Ted Cruz remains a long shot for the Republican presidential nomination. So too does John Kasich. And on the Democratic side, Bernie Sanders isn’t doing much better. But unfavorable math hasn’t stopped all three from engaging in that holiest of presidential campaign front-runner traditions: playing the running mate guessing game.

The Cruz campaign leaked to CNN that it has begun to vet possible running mates, one of whom includes Carly Fiorina. Over the weekend, John Kasich told CBS News that his campaign has also begun the vetting process, despite the fact that Kasich has won only one primary so far. And on Tuesday morning, Bernie Sanders told Morning Joe he was open to a woman as his running mate, offering up Elizabeth Warren as one option.

Time was that naming a VP was supposed to generate enthusiasm for a candidate as he (or she this time) headed into the general election. But the Cruz campaign, for one, has strongly suggested that it will might select a Veep candidate before the primary is over, to give his lagging campaign some firepower against Donald Trump. In an election season of firsts, we might even see three full-fledged presidential tickets at the Republican National Convention.