When Vice Presidents Actually Matter to the Election

A presidential running mate gets two weeks of intense coverage when they are announced, a week of attention at the nominating convention, and one debate about midway through the general election. The rest of the campaign mostly forgets they are there. Voters say they choose presidents based on the person at the top of the ticket, and the polling data mostly confirms it. A VP pick typically moves the race by one or two percentage points in either direction, often less, and the effect fades within a month.

That is the base rate. The interesting question is when a VP pick has actually mattered — when the choice swung electoral votes, shifted the campaign’s coalition, or determined the outcome in a state the ticket would not have won otherwise. The list of such cases is short. It is also instructive.

What VP picks are usually trying to do

A VP pick is doing several jobs at once, and most of them are not about persuasion. The pick has to be acceptable to the party base, defensible to the press, geographically or demographically complementary to the top of the ticket, and capable of stepping into the presidency if the top of the ticket cannot. Each of those constraints narrows the field. The candidate who satisfies all of them is usually a few rungs down from the names that dominated speculation.

A small share of the calculation is electoral. Will this person help us win their home state? Will they help with a specific demographic we are losing? Will they bring suburban voters or rural voters or independents who would otherwise stay home? These are the questions that get the most coverage during the speculation period. They are also the questions where the answers are weakest, because most VP picks do not deliver any of the things the speculation suggests they will.

The base-rate finding from political science is fairly consistent. VP picks move the race by zero to two points on average. The home-state bounce, which used to be considered standard, has shrunk in recent decades as the country has nationalized and state-level loyalty has weakened. A VP who used to deliver their home state by three points may now deliver it by less than one.

The cases where it mattered

A few specific VP picks have moved the dial enough to matter. Lyndon Johnson’s addition to the Kennedy ticket in 1960 almost certainly delivered Texas, which Kennedy needed and would not have won without Johnson on the ticket. The home-state effect was unusually large because Johnson was unusually powerful in Texas — Senate majority leader, longtime political operator, the kind of figure who could pull his state with him in a way a typical VP pick cannot.

George H. W. Bush’s selection in 1980 mattered for a different reason. Reagan’s campaign was concerned about appealing to establishment Republicans who had not warmed to him during the primary. Bush served as a bridge to that constituency. The polling movement was not enormous, but the coalitional repair was real, and Reagan’s general-election performance with moderate Republicans tracked the addition of Bush to the ticket.

Sarah Palin’s selection in 2008 mattered, but in the opposite direction. Initial polling showed a clear boost from her addition. The boost reversed within several weeks as the press coverage of her qualifications became negative. By election day, the polling effect of her selection was net negative — the campaign she joined finished slightly behind where it would have plausibly finished without her. The case is unusual because the polling movement was visible in both directions and unambiguously tied to the pick.

The cases where it did not matter

A longer list of VP picks were treated as potentially decisive at the time and turned out to be irrelevant. The pick was discussed for two weeks, dominated convention coverage, and then disappeared from the campaign’s effective strategy as soon as the general election engaged. Most modern VP picks fall into this category.

The reason is that voters in nationalized elections are evaluating the person at the top of the ticket. Demographic appeals through the VP nomination — putting a woman on the ticket, putting a person of color on the ticket, putting a southerner on the ticket — rarely produce measurable polling gains with the target group, because the target group is making decisions based on the top of the ticket. The VP can be a marginal positive or negative but is rarely the deciding consideration for anyone whose vote was actually up for grabs.

There is one exception worth flagging. A VP pick can hurt the ticket if the pick raises questions about the presidential candidate’s judgment. A perception that a candidate selected a running mate who is unqualified, ideologically extreme, or politically careless can damage the candidate at the top — not because voters care about the VP per se but because they take the pick as evidence about the presidential candidate’s decision-making. That mechanism is real and has shown up in polling in multiple recent cycles.

The succession question, which voters undercount

A vice president’s most important job is being a competent president in waiting. Nine vice presidents have become president through succession — four because of assassinations, four because of natural death in office, one because of resignation. The base rate of presidential succession within any given four-year term is small but not negligible.

Voters discount this risk because succession feels remote and presidential elections feel immediate. The VP debate that does take place during a campaign usually does not test the candidate’s readiness in any rigorous way; the format is the same ninety-minute structure as the presidential debate, and the focus is on positioning rather than on the operational questions a vice president would actually face on the first day of an unexpected presidency.

If you wanted to evaluate a VP nominee for the part of the job they may actually need to do, you would look at their record managing complex institutions, their familiarity with the federal government, their relationships with allies and adversaries, and their judgment under conditions of incomplete information. Almost no campaign coverage of VP picks evaluates these traits seriously. The coverage is mostly about ticket balance and demographic signaling, which is a much smaller question than the one the role actually presents.

What to take from the next VP pick

When a new VP is announced, the speculation about whether they will deliver a state, a demographic, or a coalition is mostly noise. The base rate is that they will not. Where to look instead: how the pick reads in terms of the presidential nominee’s judgment, what coalitional message the pick is sending to the party base, and what kind of administration the pick suggests is being built behind the candidate.

A presidential nominee who picks a careful, experienced, slightly boring running mate is signaling that they are building a governing operation rather than a campaign spectacle. A nominee who picks for ticket excitement is signaling something different. Neither approach is correct in the abstract. Both are visible from the pick itself.

The VP almost never decides an election. The VP often tells you something about how the campaign sees itself and how the candidate sees the office. That is usually the more useful signal to read.