A week after his special-election victory — and six months after his predecessor pleaded guilty to bribery — San Diego Republican Brian Bilbray was sworn in to the House Tuesday to replace ex-Rep. Randy "Duke" Cunningham.

After House Speaker Dennis Hastert administered the oath, Bilbray, 55, gave a floor speech sounding the theme he believes boosted him to victory — illegal immigration, not congressional corruption.

"We did not enjoy the situation or appreciate the problem that created the vacancy," Bilbray said. "But let me say quite clearly — what is obvious in the last few months is the greatest scandal in America is not that one man broke the law, but that 12 million illegal immigrants are in this country and Washington isn't doing enough about it."

Bilbray, who served in the House from 1995 to 2000 in a different San Diego-area district, beat Democrat Francine Busby by four percentage points with 49 percent of the vote. Both major parties spent heavily on the race in Cunningham's wealthy, heavily Republican coastal district, believing that a Democratic upset could signal serious risks for the GOP in the November midterm elections.

Bilbray will now fill out the remaining seven months of Cunningham's term and will have to run against Busby again in November. But their rematch is expected to attract far less attention.

A surfer and former lifeguard and mayor, Bilbray has served as a lobbyist for an anti-illegal immigration group since losing his House seat in 2000 to Democratic Rep. Susan Davis.

He will be taking over Cunningham's old office on the third floor of the Rayburn House Office Building. Cunningham, a former Navy pilot, is serving eight years and four months in prison after admitting taking $2.4 million in bribes from defense contractors and others.

Before his swearing-in, Bilbray said he looked forward to replacing the images of airplanes that used to decorate the walls with photos of surfboards and sailboats.

"We all need to be reminded of the tragedy that brought me here. But I also have a huge responsibility to make sure that doesn't happen again," he said.