Do Vice Presidential Picks Actually Swing Votes?

Robert Schlesinger

Ted Cruz's announcement this week that -- on the off-chance he actually lands the Republican presidential nod -- former Hewlett-Packard CEO Carly Fiorina would be his running mate was met with bemusement and amusement on the Internet. "Perhaps I should pick a running mate. ... I'm *also* not winning the Republican nomination & it seems like a fun idea," author Rebecca Traister tweeted Wednesday. "Ted Cruz to announce site of his presidential library," added The Washington Post's David Waldman. Talking Points Memo's Josh Marshall noted that "Fiorina is almost as widely reviled as Cruz himself and election and polling measures has very little political appeal to speak of at all."

READ: [Why Carly Fiorina Is Ted Cruz's Best Bet for a Running Mate]

That last observation reminds us of one of the main lenses through which such selections are traditionally viewed: To what extent does a running mate add a discreet group of voters, whether in a state or in a demographic group, to the presidential candidate's column?

There are actually a couple of answers to this question. On one level, according to political scientists who have crunched the numbers, vice presidential selections are overblown nonfactors -- they don't add tickets. But there are more things in campaigns and elections, to paraphrase Shakespeare, than are dreamt of in data-mining -- and there are areas where a running mate can shape perception of a candidate if not measurably move numbers.

First the hard data. Does tapping someone from a swing state in the hopes of moving it into your party's column make any sense? "Statistically the effect of a running mate's electoral appeal in their home state is zero," says Kyle Kopko, a political scientist at Elizabethtown College who recently co-authored "The VP Advantage: How Running Mates Influence Home State Voting in Presidential Elections." That book studied voting and survey data going back to the 1884 election and found that but for a very narrow set of circumstances voters vote the top of the ticket. The exception is when a running mate comes from a small state from whence they are deeply entrenched -- think Joe Biden from Delaware in 2008 or Ed Muskie from Maine in 1968. And those examples beg the question of how often flipping a single small state would make an electoral difference (one answer: Had Al Gore tapped then-Gov. Jean Shaheen of New Hampshire as his running mate in 2000 he might have won the Granite State and the election). Pols from big states, on the other hand, add nothing to the ticket, which will come as sad news for those hoping that Ohio Gov. John Kasich could swing the Buckeye State for, presumably, Donald Trump.

[OPINION: 5 Reasons to Celebrate Ted Cruz Naming Carly Fiorina as His VP Pick]

What of demographics? If Hillary Clinton selects a Latino vice presidential candidate ( think Housing and Urban Development Secretary Julian Castro) or if Cruz wrests the nomination from Trump can she expect for a Hispanic boost or he one from women? Not so much. Kopko and his co-author, Christopher Devine of Mount Vernon Nazarene University, looked at whether ground-breaking running mates -- Geraldine Ferraro in 1984, for example, or Catholic Sargent Shriver in 1972 -- bolstered the ticket in their demographic groups. "They are viewed more positively by [those] voters," says Kopko. "But those positive feelings don't necessarily translate into votes."

Kopko and Devine's findings are largely in line with what other political scientists have found. "The net impact of vice presidential selection is at most 1 percentage point," political scientists Bernard Grofman and Reuben Kline wrote in Presidential Studies Quarterly in 2010, for example. (As with everything in politics there are dissenting views; a pair of University of Virginia political science PhD candidates recently published a study in which they argue running mates can add 3 percentage points in their home states.)

But just because you can't measure the vice presidential effect it doesn't mean it doesn't exist. It's important to think of potential veeps not as candidates in their own rights or as individuals on a ticket but rather as part of the litany of characteristics that reflect upon the presidential candidate: They are, as has been often observed, the first presidential decision upon which the public can judge a would-be chief executive. "Vice presidential candidates can help to bring the party together and they can help to change -- at the margins perhaps -- the image of the presidential candidate," says Devine, Kopko's co-author.

There are other ways, depending upon the atmospherics, that the pick can become part of the calculus of evaluating a presidential candidate without being a game-altering equation themselves. They can reinforce the candidate's core message or image, as when young Southern centrist Democrat Bill Clinton picked young Southern centrist Democrat Al Gore; they can provide reassurance to either discreet groups of voters (Ronald Reagan reaching out to establishmentarian Republicans by tapping George H. W. Bush, for example) or the electorate at large (George W. Bush and Barack Obama shoring up experiential deficits by tapping Dick Cheney and Joe Biden, respectively).

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The politics of the vice presidency and whether the job can serve as an olive branch or salve in a fractured party or a leery general electorate could also take on a unique hue this summer if the #NeverTrump faction of the GOP manages to rally and force a contested convention. "If the nomination is decided well ahead of the convention it gives people's passions and tempers time to cool down," says Joel Goldstein, an expert in the vice presidency at St. Louis University. "If you have to make all these decisions right at the convention when you've just gone through the presidential balloting it doesn't give the rawness of emotions time to heal."

Throw in the fact that if it is Trump -- who is reviled by much of the official GOP -- and if his poll numbers against Clinton remain dismal, leaving his campaign with a loser's stench, he could have a hard time finding someone to tell, "You're hired."

It would be the sort of sideshow that would only be in keeping with this weird political year; but it probably wouldn't have a direct effect on the next president.

Robert Schlesinger is managing editor for opinion at U.S. News & World Report. He is the author of "White House Ghosts: Presidents and Their Speechwriters." Follow him on Twitter or reach him at rschlesinger@usnews.com.