We’ll hear a thousand times in the next year that the last vice presidential running mate who made a decisive difference was Lyndon Johnson in the squeaker election of 1960, carrying Texas and some other Southern states that John F. Kennedy might have lost on his own. That’s true — a Johnson is a rarity, but then again, maybe we’re overdue for another LBJ. Many VP candidates have had some impact, though the effect, while minor, has often been negative and distracting, modern examples being Spiro Agnew (R, 1968), Thomas Eagleton (D, 1972 — Sargent Shriver ended up replacing him on the ballot), Geraldine Ferraro (D, 1984), Dan Quayle (R, 1988), and Sarah Palin (R, 2008).

In 2016, the potential exists on one or both sides to nominate a VP candidate who enhances the ticket and maybe even helps carry one of the few real swing states. It’s pointless to list Republican possibilities because we do not yet know the identity of the GOP presidential nominee. Privately, Republican leaders mention a “dream ticket” of Sen. Marco Rubio of Florida and Gov. John Kasich of Ohio, who together might deliver 47 swing-state electoral votes. At this early juncture, it might be better termed the “pipe dream” ticket.

Hillary Clinton’s VP choices are limited because of the wipeouts the Democrats have suffered at other levels in Obama’s two midterm elections. The most mentioned and logical possibilities are Sen. Tim Kaine of Virginia, Sen. Sherrod Brown of Ohio, and perhaps Gov. John Hickenlooper of Colorado. Should the Republicans put Rubio on their ticket in either position, then Clinton may want to pick one of the Castro brothers, Secretary of Housing and Urban Development Julian Castro or U.S. Rep. Joaquín Castro of Texas, to solidify her standing with Hispanics.

The Democrats may not have a long list of possibilities, but they have one significant advantage in the 2016 Veepstakes: Theirs is the second convention next summer, so Clinton can make her decision after seeing what the GOP ticket looks like.