Who will be the next “Mr. Republican”? While the race for the 2016 Republican presidential nomination gets underway, there is another, more informal race going on as well. Since the Second World War, there have been a handful of elected Republicans who have distinguished themselves not by winning the White House, but rather by setting the party’s ideological direction.

The first Mr. Republican was Robert A. Taft, the Ohio senator who served as the most scathing conservative critic of FDR and the New Deal, and who later warned that America’s Cold War entanglements threatened freedom at home. His successor was Barry Goldwater, who called for rolling back the frontiers of the welfare state at home and communism abroad, and through his crushing defeat paved the way for the Great Society and a vast expansion of federal power. Goldwater inspired a generation of conservatives, including Ronald Reagan, who eventually overpowered the moderates and liberals who once played a central role in the party.

Jack Kemp crafted a less hard-edged and more optimistic “bleeding-heart conservatism,” which celebrated economic growth as a painless way to finance rising social expenditures. And Newt Gingrich, as architect of the first Republican House majority in a generation, offered a combustible mix of high-minded techno-utopianism and scorched-earth partisanship that transformed American politics.

Last week’s Conservative Political Action Conference saw a whole host of Republican standouts jockeying for position, including Kentucky Sen. Rand Paul, Texas Sen. Ted Cruz, Florida Sen. Marco Rubio, and New Jersey Gov. Chris Christie. But with the exception of Rand Paul, these men aren’t offering distinctive new visions for the GOP.

To be the next Mr. Republican (or Ms. Republican, if the current bench included more women), you need to offer a full complement of policy positions and a theory of how they fit together. The closest we’ve come to a Mr. Republican in the post-Bush years might have been Jim DeMint, the former senator from South Carolina. DeMint’s embrace of the Tea Party insurgency played a key role in its early success, and in its early failures. But when DeMint left electoral politics behind to run the Heritage Foundation, his pronouncements lost the weight that comes from being accountable to voters. Tom Coburn, the senator from Oklahoma, has the intellect and the political shrewdness the role of Mr. Republican demands, but his decision to retire from office removes him from the picture.