David Perdue’s decision to target the U.S. Chamber in the final days of his GOP Senate runoff was more a page torn from the family playbook than an act of desperation.

In 2002, upstart Sonny Perdue was shocked, baffled and outraged by the fact that a national political group known for reflexively endorsing Republicans instead decided to side with Democratic incumbent Gov. Roy Barnes.

In that case, it was the National Rifle Association. Perdue challenged Barnes to a shotgun duel – all right, a skeet shoot (which never happened) — and campaigned against the NRA as one of those many special interests unfairly dominate our civic life.

When Perdue won, overturning the political status quo, the NRA found itself sitting in time-out.

Flash forward a dozen years. Sonny Perdue’s cousin David found himself on the outs with another national organization that he thought should have been well-satisfied with his business background.

Instead, the U.S. Chamber backed U.S. Rep. Jack Kingston, R-Savannah, who – after 22 years in D.C. – was a known commodity. The group poured $2.3 million into the race against Perdue – the most of any outside group dipping into the contest. A group flush from having its way in Mississippi last month, carrying U.S. Sen. Thad Cochran across the finish line.

Like his cousin before him, David Perdue began campaigning against the Chamber as one of those special interest groups in Washington that need to be reined in. He began talking about the need to reduce legal immigration into the U.S., a key Chamber concern. In a last round of TV ads, Perdue used the Chamber endorsement to question whether Kingston’s opposition to immigration reform was indeed sincere.

The Tweet of the night may have come from Kingston supporter Erick Erickson, the conservative talk radio host:

Was able to convince A LOT of people to back candidates I was supporting, but the Chamber of Commerce endorsement of Kingston hurt him badly

Outside of Jack Kingston himself, the U.S. Chamber became the biggest loser of the evening.