Doug Hampton's campaign to bring down the man who slept with his wife continues.

Hampton's latest blast at Sen. John Ensign (R-NV) came in a sit-down with ABC News's Nightline. In excerpts teased on the ABC News site, Hampton doubles down on his contention that the $96,000 he and his wife received from Ensign's parents, after the affair was discovered, was a severance package, not a gift as Ensign has claimed. A severance payment would have violated campaign-finance laws.

Hampton said it was "crystal clear" that the payment was severance. "I took notes. I've shared those notes. They're well documented. They were clearly what he deemed as severance."

The Ensign camp has described the payment as part of a "pattern of generosity," showed by the Ensign family to the Hamptons.

Hampton ridiculed that claim to ABC. "Pattern of generosity?" he said. "Oh, hey, listen, 'We realize our son's having an affair with your wife, maybe some money will help.' It's ridiculous!"

But could Hampton's public campaign be counter-productive? The Justice Department may be considering a criminal probe of whether Ensign violated campaign-finance law, both with the payment to the Hamptons, and by reportedly arranging for Hampton to lobby his staff after Hampton had left Ensign's employ. But a former DOJ prosecutor told Politico yesterday that by talking to the media, Hampton is making himself less valuable as a potential witness. "Every time [Hampton] speaks, he's seriously undermining his own credibility as a witness and the viability of prosecution. It's just not what you want to have happen from a prosecutorial standpoint."

It probably makes him feel good though.