Although the field of 2020 presidential candidates is huge, none of them hails from Louisiana.

That means regardless of how the next election is decided, Zachary Taylor will remain, for the foreseeable future, the only president from Louisiana to have held the office.

Taylor, a military hero of the Mexican-American war, was living in Baton Rouge when he was elected president as the Whig candidate in 1848. But he lasted only about a year, dying in office of what might have been cholera, though historians are still arguing the point. He was succeeded by his vice president, Millard Fillmore, who went about trying to reverse a lot of his predecessor’s decisions.

The lesson here, one often lost on voters, is that it’s a good idea to pay attention not only to who’s running for president, but who’s running for vice president.

Author Jared Cohen makes the point in a new book, “Accidental Presidents,” which examines the leadership of eight men who became president on the deaths of their predecessor. That leaves out Gerald Ford, who became commander-in-chief when Richard Nixon resigned in 1974. Ford was not elected to a full term on his own but has grown in public estimation over the years.

Suffice it to say that no one running for president today evokes the leadership style of Millard Fillmore as a model of how they hope to lead. After serving out Taylor’s term, he faded into obscurity, declining the Whig party’s nomination in 1852. The party itself is now a historical footnote.

Zachary Taylor, Louisiana’s only president, was lifelong Army man with no interest in political office

But Cohen points out that Fillmore’s ascendance to the presidency had at least one major policy consequence. Taylor wouldn’t have been likely to approve the Missouri Compromise of 1850, a legislative deal to keep the peace between free and slaveholding states. Fillmore supported it, delaying the outbreak of civil war.

“We’ve been lucky in that no president has died in office since 1963 and while we hope our unprecedented period without an abrupt transition endures, it is inevitable that there will be a death in office,” Cohen tells readers. “Rather than prepare, we seem likely to leave any future outcome to chance and luck.”

That’s a sobering prospect for the 2020 presidential campaign season, especially when most of the leading candidates, including the incumbent, would be in their seventies when inaugurated in 2021.

So maybe, as we focus so much on who’ll be the next leader of the free world, we should think a little more about who’s the second in command.