South Carolina’s political elite have been atwitter since Sept. 20 over the state Supreme Court’s 3-2 decision to retroactively approve the Charleston County Republican primary do-over, which revived Paul Thurmond’s state Senate bid after he was removed from the ballot for failing to properly file his statement of economic interests.

But while the majority’s justification of the new primary is strained at best, and we can all hope the court will accept the opportunity that the plaintiffs are offering it for its own do-over, the practical effect of the Thurmond Rule should be fairly limited. It might apply to only one other race.

The same is not true of the much less-noticed part of the ruling that rewrote the “public official” exemption, which is the part of the law that has fueled as much of the anger over this year’s ballot purge as the purge itself. As a result, we could face yet another purge of the remaining candidates, with just six weeks before the election.

Among those at risk is Aiken Republican Deedee Vaughters, who is challenging Lexington Sen. Nikki Setzler in District 26 and who wasn’t required to file a new disclosure report according to the understanding of the law that has been in effect for 20 years.

To understand the problem, we need to step back to the spring, when candidates filed to run in this year’s elections.

By all accounts, Mr. Thurmond complied with a 2010 law that required most challengers to file an online statement of economic interests when they became candidates.

But like 250 other candidates, he did not turn in a paper copy of that report along with his intention of candidacy, as a 1992 law requires.

Those other candidates were kicked off the ballot after May and June Supreme Court orders that, correctly, said filing electronically didn’t relieve candidates of having to turn in paper reports.

Incumbents running for re-election didn’t have to turn in paper copies of the reports as long as they had a current report on file at the time they filed for re-election. Neither did any other “public official” – generally elected and appointed officials – who had a current report on file from April 2011. So a city council member running for the House or, as with Ms. Vaughters, a member of the state Lottery Commission running for the Senate was entitled to the exemption if the 2011 report was on file.

After the court ordered the political parties to purge their candidate list of people who had not complied with the law, Mr. Thurmond told party officials that he met the exemption because he was a part-time municipal prosecutor. That sounded reasonable, so they let him stay on the ballot. But Democrats discovered that he had never before filed a report as a prosecutor, and that in fact the report he filed this year wasn’t as a prosecutor but as a Senate candidate. They sued, and last month the trial judge said he was not the Republican nominee.

If the Supreme Court had adopted the trial judge’s reasoning on that point, then the only problem would be the fact that the judge also said the Republicans could hold a new primary. Instead, the court cited a different reason for declaring that Mr. Thurmond was not the Republican nominee: The only people who qualify for the exemption, the court said, are public officials who are seeking reelection to the same office.

The court had actually said that in its June ruling, but that wasn’t the main thrust of the order, and most people familiar with the ethics law assumed the court made an error, perhaps using “the office” where it meant “an office.”

A lawyer who has been involved in the ballot litigation told me on Friday that Republican and Democratic lawmakers had a general understanding that they didn’t want to challenge each others’ candidates who met the 20-year-old interpretation of the “public officials” exemption.

Judges ignored that new definition of who is exempt, even as they made rulings based on the May and June rulings. The Election Commission says Circuit Court judges have rejected challenges to at least five “public official” candidates. The most recent ruling was issued the day before the Supreme Court’s order last week, in favor of Ms. Vaughters.

I wouldn’t be surprised to see those decisions appealed and new lawsuits filed, and I don’t see how the Supreme Court could allow those candidates to stay on the ballot – unless it reverses its reasoning in the Thurmond case.

The court said its interpretation of the exemption was the only “logical construction” of the statute; it then added several sentences that I can’t make heads or tails of no matter how many times I read them but that seem to imply that the court believes the Legislature had deliberately set a trap for challengers. It had not.

The reason the Legislature required candidates to turn in their statements of economic interests at the same time they filed for office was to ensure that every candidate on the ballot had turned in that report.

The reason it exempted “a public official who has a current disclosure statement on file” was that ... those officials already had a report on file.

There was no reason for them to file a new one.

It didn’t matter if a Senate candidate had filed her report because she was a member of the Lottery Commission, or if a House candidate had filed his report because he was a member of a county council.

What mattered was that some basic level of information was available to the public.

When a law is clear and not in conflict with any other law, the court doesn’t have to understand what the Legislature was trying to accomplish.

In fact, as our court noted in the original ballot case, it does not have the right to consider what the purpose was. But when laws seem to conflict, the court must try to ascertain what the Legislature’s intention was.

That’s what it did in this case, and I think it was making a good-faith effort. But it completely misunderstood that intention.

Cindi Ross Scoppe is an associate editor with The State newspaper in Columbia.