AFTER THE GOVERNOR finished his House-bashing publicity stunt with the squealing, defecating piglets dubbed “Pork” and “Barrel,” he might well have trotted the livestock across the lobby to the Senate chamber, where they could have bellied up to a different kind of trough the senators were preparing.

While attention focused on Mr. Sanford’s grossly undignified critique of the House’s childish veto tantrum, the Senate was quietly approving a measure to let lobbyists line legislators’ pockets and let the special interests who employ the lobbyists more easily line their stomachs with food and liquor.

The legislation, which faces a final Senate vote Tuesday before going back to the House, could mark the General Assembly’s fastest retreat ever from good-government reform.

The 1991 ethics law, passed after the federal government exposed the free exchange of cash for favors between lobbyists and legislators, wisely prohibits lobbyists from making campaign donations to legislators. But a loophole that was quickly discovered and exploited allows a lobbyist to “unregister” when the General Assembly adjourns for the year — or for an evening, for that matter — make all the $1,000 donations he wants to the legislators he’s been paid to influence, and then re-register before the bell rings on the start of the next legislative day. It was just a year ago that the Legislature finally plugged that loophole, barring campaign contributions for the entire calendar year in which someone is registered as a lobbyist.

But on Thursday, the Senate voted unanimously to open it back up — in time to make sure the lobbyists will be able to write fat checks for the primary elections nine days from today.

On top of that, the Senate voted to allow a “freshman caucus” to join the list of legislative committees, delegations and caucuses that can hit up special interests for free meals and booze. (Special interests would still be prohibited from wining and dining individual legislators — at least for now.)

Both bad-government measures were attached to a House bill that had minor sins of its own. The original bill makes it more difficult for the public to find out about those free meals and drinks, and it removes a provision that prevented lobbyists from “facilitating” campaign donations; that could make it easier for special interests to tie their campaign donations to specific votes. That was already a bill of dubious value. The Senate’s amendments make it a bill that cannot be justified.

If senators care more about serving the public than serving themselves, they will reconsider their action. If they don’t, the House should refuse to accept the Senate changes. And if all else fails, Gov. Mark Sanford should waste no time vetoing this measure. One of the few things he has to show for two years in office is last year’s long-overdue reform of the state’s ethics and campaign finance laws. The last thing he should want to do is oversee the unraveling of those reforms.