Why the number of swing states is dwindling
© Getty Images

After wrapping up the Republican nomination in early May, Donald TrumpDonald TrumpBipartisan group of mayors asks for immigration reform Obama offers laments and optimism at last presser Overnight Energy: Trump's EPA pick faces Congress | 2016 is the hottest year on record MORE continued visiting primary states, like California and New Mexico, that in all likelihood won't be decisive in the general election. More recently, he made a trip to Indiana, the most Republican state in the Midwest, although that was an audition for Gov. Mike PenceMike (Michael) Richard PencePence: I'm ‘confident’ in Trump’s health pick Pence: NATO mission 'will go forward' Overnight Defense: Obama defends Manning commutation after backlash | Mattis clears Senate panel MORE, now Trump's running mate. Presumptive Democratic nominee Hillary ClintonHillary Rodham Clinton Fox News was Trump voters' top source for election news: Pew Democrats remind Trump that he must govern for all citizens Chelsea Manning's redemption proves how far WikiLeaks has fallen MORE, too, has spent time in non-decisive states, like New Jersey, though that was to critique Trump's business history in Atlantic City. But now that the conventions are upon us, recent history suggests that both candidates will, or at least should, narrow their travel.

ADVERTISEMENT
While Trump is unpredictable enough that his plans may be anyone's guess, we should expect the Clinton campaign to run a textbook race, focusing almost exclusively on the states likely to decide the election. In 2012, the members of both presidential tickets held post-convention visits in just 12 states, with a third of those visits coming in just a single state: Ohio, the historic maker of presidents that I explore in-depth in my new book, "The Bellwether: Why Ohio Picks the President." Campaign ads were similarly concentrated.

It wasn't always this way, though.

Two days before he lost a very close presidential election to John F. Kennedy, then-Vice President Richard Nixon found himself in Anchorage, Alaska. A major part of his campaign had been a promise to visit all 50 states, and he saved Alaska for the end. In Anchorage, he noted the history he had made: "This is indeed, a historic moment. It is one that will never be duplicated. This is the first time in the history of the United States that a candidate for the presidency of either party has visited all of the 50 states of this country."

Nixon's pledge became a target of easy criticism as he used valuable time at the end of the campaign. "All through the campaign," wrote Theodore White in his definitive "The Making of the President, 1960," "as the race narrowed and it became obvious that it would be won or lost in the teetering industrial northeastern states, Nixon was cramped by his public pledge — so that on the last weekend of the campaign, as Kennedy barnstormed through populous Illinois, New Jersey, New York and New England, Nixon found himself committed to fly all the way north to Alaska, which offered only three electoral votes."

Even though it seems silly now, though, Nixon's vow made at least some sense in 1960. That year, in what would be an essentially 50-50 split in the national popular vote, 20 of the 50 states were decided by 5 percentage points or less, including big states like California, Illinois, Michigan, New Jersey and Texas. The same thing happened 16 years later in Jimmy Carter's 2-point national win over then-incumbent Gerald Ford. But by 2012, in Barack ObamaBarack ObamaBipartisan group of mayors asks for immigration reform Overnight Tech: Five tech takeaways from Commerce pick's hearing | Groups accuse Facebook of 'censorship' | Wireless auction moves ahead | Pokemon Go at Davos Lanny Davis: Farewell, President Obama: Your legacy as one of the best presidents is secure MORE's 4 point victory over GOP nominee Mitt Romney, just four states were decided by less than 5 points.

As I note in "The Bellwether," Ohio has the best record of picking presidential winners over the last 30 elections — only two times in that period has it voted for the loser (1944 and 1960). It also, on average, deviates only about 2 points from the national voting, also the best mark amongst the states. But a state like Ohio is arguably more important now than it was a half-century ago because the number of states like it — those that vote close the national average — are dwindling, as the examples from 1960, 1976 and 2012 make clear. In fact, Nixon actually won Ohio in 1960, one of the rare times it voted for the loser.

Let's look at this another way, though. In 1960, about 75 percent of the nation's electoral votes were in states that voted less than five points from the national average, one way or the other. So in that election, where the national popular two-party vote was basically tied at 50-50, any state that voted 54-46 one way or the other, or closer, would be included. As the country has become more sorted, partisan and polarized over time, with fewer crossover voters and more ideologically cohesive parties, that number dwindled, so that in 2012, just about 30 percent of the nation's electoral votes were in states that voted within less than 5 points, either way, of the national average.

Included in that group are the competitive states that Americans have become accustomed to in recent years, like Colorado and Virginia — which are new to the group of highly competitive presidential states — as well as states that have longer histories reflecting the nation, like Nevada and Ohio, which nearly always vote for the presidential winner, as well as Florida, the biggest state in the Union that has been perennially competitive over the past handful of elections.

Teddy White rolled his eyes at Nixon's 50-state ploy in 1960. Nowadays, even a 25-state strategy would elicited the same reaction.

Kondik is managing editor of Sabato's Crystal Ball, a nonpartisan newsletter on elections produced by the University of Virginia Center for Politics. He is the author of the new book "The Bellwether: Why Ohio Picks the President."