Faced with compelling evidence of his campaign fund abuses, Charleston County’s senior state senator, Robert Ford, did the right thing on Friday by resigning the seat he has held for 20 years.

Presumably it’s the end of a long, often controversial career in politics and the public realm. Though after the recent 1st District election, who knows?

Mr. Ford came to Charleston as a civil rights activist during the 1969 hospital strike, and remained here as a community organizer. In 1974 he was elected to Charleston City Council, where he served for 18 years. Outspoken and gregarious, Mr. Ford appeared to be largely consumed by his political work, both as a councilman and as a state senator.

Too bad he didn’t pay more attention to the laws prohibiting the use of campaign funds for personal purposes. They are a fundamental requirement for public service, and Mr. Ford had been around long enough to know them inside and out.

The violations cited by the Senate Ethics Committee were serious and numerous, and included the use of campaign contributions for car loans, personal health care and items from adult stores.

Maybe those “adult” items were legally purchased for campaign aides as gag gifts, as Mr. Ford insisted.

But it’s clear that other funds were not spent solely on public service projects, as he maintained.

It’s clear, too, that Mr. Ford’s ethical woes weren’t simply caused by “horrible bookkeeping,” as his attorney contended.

The committee also found that Mr. Ford failed to report numerous donations and personal loans, and that he altered copies of financial documents.

The committee has forwarded the ethics case, including what it called “overwhelming” evidence against the senator, to Attorney General Alan Wilson’s office.

Mr. Ford, a Democrat, has previously been questioned on comparatively minor ethical matters, such as using his Senate stationery to promote a political candidate (John Edwards in the 2004 race for the Democratic presidential nomination) or to promote himself as a used car salesman. But the Senate Ethics Committee never found against him until Friday.

Mr. Ford, a Louisiana native, has taken justified pride in serving on the front lines of the civil rights movement — having been arrested 73 times, according to his official biography in the “Legislative Manual.”

During his years in the Senate, Mr. Ford became an advocate for racial reconciliation. He played a key role in the 2000 compromise that brought the Confederate flag off the Statehouse dome, and served as an effective proponent for the African-American monument at the Statehouse.

As such he formed what was initially considered a surprising alliance with Senate President Pro Tempore Glenn McConnell, a conservative Republican who is now the state’s lieutenant governor.

Now Mr. Ford will also be remembered for his ethical lapses and for his sudden forced departure from the Senate.

That’s a shame — and a painful reminder to other lawmakers of their duty to follow the rules on the use of campaign funds.