Columbia, SC — FEW IF ANY decisions Gov. Nikki Haley will make hold the potential import to our state and even our nation as who will replace retiring U.S. Sen. Jim DeMint.

That person will join the Senate at a critical time in our nation’s history, as two hyper-polarized political parties struggle over tax and spending policies that could either set us on a course to restore fiscal sanity or else plunge us back into recession, or worse.

Even if the Congress and the president manage to avert the fiscal cliff while Mr. DeMint is in office, most of the actual work, and likely many of the decisions, will remain after his replacement is sworn in. And as one of just 100 members of a body that gives far too much negative power to each individual, even an unelected freshman could do great damage to the republic. Or, one hopes, do great good.

Assuming the governor’s senator doesn’t do anything terribly wrong, he or she will be well-positioned to win the special election for the remainder of Mr. DeMint’s term in 2014, the election to a new term in 2016 and, given our history, a potentially long career in the world’s most exclusive club.

Much of what Gov. Haley has said about her selection criteria is sound: She won’t arrange to have herself appointed. She won’t appoint a placeholder. She will appoint a conservative — which reflects the values that S.C. voters consistently demonstrate at the polls.

Not so obviously sound is her pledge to pick a “fighter.” If that simply means an aggressive advocate who isn’t a push-over, that’s good; if it means someone who will consistently thwart the will of the majority, then that’s bad.

Governors and presidents have the right to be rigidly ideological and uncompromising; it’s not wise, but it’s their right. Legislators do not.

Legislators are elected to be part of a body. The fundamental job of a legislator is to work with other legislators, of both similar and different opinions, to come to a consensus on how to achieve the best results for our nation. Their job is not to push their opponents into positions that will make it easier to defeat them at the next election, and our nation deserves better than for South Carolina to send it another senator who thinks it is.

Clearly unsound is the governor’s dismissal of the need for experience. No, we don’t have to have someone who has been in elective office for decades. But we do need someone who has been publicly vetted, elected and served in elective office.

In saying that experience doesn’t matter, Gov. Haley pointed to the state’s four second-term U.S. representatives, whom she said have quickly made their mark despite being new. But while they’re new to Washington, none of them is new to elective office. They’ve all held previous office; they are known quantities. Two of them, U.S. Reps. Tim Scott and Trey Gowdy, are said to be on the governor’s short list, as is former Attorney General Henry McMaster.

Her other two candidates, former First Lady Jenny Sanford and DHEC Director Catherine Templeton, have never even run for office. Few people who aren’t political insiders would even recognize Ms. Templeton’s name. And although we’re all familiar with Ms. Sanford and her politics, it’s not as someone who has ever been called on to make decisions about public policy.

Ms. Templeton and Ms. Sanford both appear to be quite intelligent and capable, but they have not gone through the rigors of an election campaign, which can reveal important character traits in a way nothing else does. They have not had to balance the competing demands of voters and lobbyists and fellow lawmakers and the public good, all in a very public arena.

Frankly, we’re not comfortable supporting candidates for statewide elective office who have never held elective office. But at least they have to go through the campaign. It’s one thing for voters to decide to take a chance on someone who has never held elective office; it’s quite another for one individual to make that decision, even when that individual is our governor.

We don’t mean to suggest that the governor must appoint Mr. Scott, Mr. Gowdy or Mr. McMaster; there are plenty of other capable people who meet the minimum standards for the job. But her other two candidates are not among them.