Only months ago, Sen. Barbara Boxer and her Republican colleague, Sen. David Vitter of Louisiana, sang each other's praises on the Senate floor as lawmakers overwhelmingly approved the water-infrastructure legislation they crafted together.
It's all water under the bridge now.
On Friday, Vitter fired off a letter to the Senate Select Committee on Ethics asking the panel to investigate Boxer and Senate Democratic leader Harry Reid of Nevada over what Vitter describes as an "intimidation and payoff scheme."
Vitter accused Reid and Boxer of attempting to punish him for insisting that the Senate vote on an amendment related to the federal health care overhaul. Vitter this week blocked the Senate from moving forward on a bipartisan energy bill, irritating Reid and other Democratic leaders.
The newspaper Politico reported this week that Senate Democrats were drafting a countermeasure aimed at Vitter and the Republicans who support his amendment.
Vitter's amendment aims to end health-insurance subsidies for members of Congress and their staffs when the president's health-care law takes effect in January.
According to the Politico report, the draft language of the Democrats' amendment threatened instead to end the health-care payments for the senators and staffs of senators who voted for Vitter's amendment - and to any lawmaker or aide who was determined by the ethics panel to have "engaged in the solicitation of prostitution."
In 2007, Vitter's name surfaced in the "D.C. Madam" prostitution scandal. Vitter apologized then what he described a "very serious sin." The ethics committee declined to investigate Vitter, and he won re-election in 2010.
Citing the Politico report in his letter Friday, Vitter asked the ethics committee to investigate whether Reid and Boxer were engaged in "political scare tactics, personal attacks, and threats that would affect each Senator's personal finances (i.e. bribery)."
Vitter made another request: that Boxer, who happens to chair the ethics committee, recuse herself unless she could prove that neither she nor her staff participated.
And if the committee found that Boxer had been involved, he wrote, "the minimum consequence for such behavior should be her removal from the committee."
Through a spokesman Friday, Boxer had this to say:
"Senator Vitter has manufactured a bizarre and phony attack that demeans the Senate."
PHOTO: In an April 15, 2008 file photo Sen. David Vitter, R-La., asks a question of a witness during a subcommittee's hearing on Capitol Hill in Washington. Associated Press/ Susan Walsh.