WASHINGTON — The Illinois congressional seat that former House Speaker Dennis Hastert once held for 20 years may see a Hastert comeback.

Hastert's son, Ethan, is running as a Republican for the seat now held by Democratic Rep. Bill Foster, a former physicist who succeeded the elder Hastert after a special election early in 2008.

Ethan Hastert said Thursday he initially had no interest in becoming a congressman, but his view changed after watching the federal budget deficit balloon. He acknowledged that his father was often criticized, even by fellow Republicans, for helping to increase the deficit. He said he shares that frustration about deficits.

"I think it's fair to say that Republicans lost their way on spending," Ethan Hastert said. "We've got to change but it's a change in quantity, not quality."

Dennis Hastert, whose eight years as speaker made him the longest-serving Republican to hold the job, has been a registered lobbyist for the past year, with Dicksten Shapiro LLP. He said he has not really lobbied lawmakers, but has been a senior adviser to clients such as the country of Turkey. Hastert, who lost his powerful post as speaker when Democrats took control of Congress after the 2006 elections, resigned in late 2007.

Of his son, Hastert said, "He's his own person. He really has to be an entrepreneur on the issues."

It is unclear whether Ethan Hastert, 31, would have any GOP primary opposition. Businessman Jim Oberweis, the GOP nominee last year, is supporting him, providing a donation included in the $75,000 Hastert has generated in recent weeks.

State Sen. Chris Lauzen, who lost a bitter GOP primary fight to Oberweis, said he expects to decide later this year whether to run again. He said Democrats will not be at a shortage of issues should Hastert be the candidate.

For two years, until June 2002, Ethan Hastert worked in former Vice President Dick Cheney's office as a special assistant to Lewis "Scooter" Libby. Years later, Libby was convicted on felony charges of obstruction of justice and lying to investigators about his conversations with reporters.

"If they want to run against the former vice president, fine," Ethan Hastert said. "The fact of the matter is I am going to be on the ticket."