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Before a recent predawn vote on Medicare, Republican lawmakers pleaded with fellow GOP Rep. Nick Smith (search) to change his vote and support the bill. Was it just another case of political arm twisting or something more?

The exchanges that morning on the floor of the House, when a handful of votes could decide the fate of the Medicare bill (search), have put the retiring Michigan congressman in the middle of a storm of charges and calls for an investigation.

Smith stood firm and voted against the bill, which passed by five votes on Nov. 22. But shortly afterward he leveled an explosive charge: Unnamed lawmakers and business interests had promised substantial amounts of money to his son's congressional campaign if Smith voted for the bill and had threatened to support other candidates if he didn't change his vote.

By Friday, Smith was backpedaling, saying his earlier suggestion of a bribery attempt was "technically incorrect." By that time, the Justice Department was reviewing requests for an inquiry.

And Republicans were mounting a defense, with former House Speaker Newt Gingrich telling C-SPAN on Friday that Smith was "a disgruntled retiring member" who was the victim of nothing more than the usual treatment in a close vote.

"I just think this is one of those occasional Washington mountains that's being built out of less than a molehill," Gingrich said.

Smith, a fiscally conservative Republican and farmer from Addison, Mich., refused to support the bill because he said it would cost too much. Smith said he was subject to intense pressure from Health and Human Services Secretary Tommy Thompson and House Speaker Dennis Hastert (search), R-Ill.

On his Web site the day after the vote, Smith said "other members and groups made offers of extensive financial campaign support" for his son, Brad, an attorney who is running to take the seat when the elder Smith steps down next year. Neither Smith nor his son will say who spoke to Smith that morning.

Hastert's office has said the speaker only suggested that a vote for the Medicare bill would help Brad because it was a popular bill.

Smith partially reversed himself Friday.

In an interview, he said someone outside of Congress had offered his son "substantial and aggressive campaign support" and Smith assumed that meant financial support. But he said it was "technically incorrect" to say money was offered.

Smith also said Republicans weren't pressuring him to back away from his previous comments.

He said he wrote the column because he was proud that his son had told him to vote against the Medicare bill despite the threats. He also hoped to offset any damage to the younger Smith's campaign.

Smith said he didn't think the incident met the legal definition of bribery. Under federal law, it is illegal to directly or indirectly promise something of value to a public official in order to influence a vote.

"If bribery is saying 'Look, you're not going to get that bridge in your district unless you vote for this,' then I'm sure the Justice Department is going to have a full-time staff looking into this," he said. "There's just a lot of political bluster on the floor."

Instead, he says the calls to investigate are politically motivated.

Terry McAuliffe (search), chairman of the Democratic National Committee, is among those who has asked the Justice Department to investigate, along with a campaign finance watchdog group and the Citizens for Responsibility and Ethics.

The department said it would review the complaints.