The Republican nomination for president is completely up for grabs, but there's a lot of agreement on who the vice presidential pick should be: Marco Rubio, the freshman senator from Florida. My contacts in the Mitt Romney camp are boasting: "Doesn't a Romney-Rubio ticket sound great?" One senior Romney advisor told me: "We think that could be a dream ticket." Operatives from the pack of other wannabes are thinking ahead to the same Rubio marriage with their candidate.

Mr. Rubio was pressed to join the presidential sweepstakes, but declined because of his newcomer status to the Senate. But he has several appeals as the number two man on the ticket. First, he is a big vote getter in the electoral swing state of Florida, which is a must win state for Republicans. Second, his Hispanic heritage is a proven vote-getter with Latino voters. A third draw is that Mr. Rubio has indisputable conservative and tea party credentials, which would make him a natural pair with Mr. Romney, who is seen by some as a moderate, corporatist Republican. The same logic would apply if Minnesota's Tim Pawlenty won the nomination.