With a vote to end filibusters of judicial nominations all but certain, Senate Democrats are upping their efforts to tie the move to Majority Leader Bill Frist’s (R-Tenn.) 2008 presidential ambitions.

The Democratic Senatorial Campaign Committee will send out an e-mail to supporters this week that seeks to paint the fight over nominees as part of the evolution of Frist’s presidential ambitions and urges donors to stop the Tennessee Senator’s national campaign in its tracks.

“The reckless right wing of the Republican party is ready to anoint Senate Majority Leader Bill Frist as their next candidate for President of the United States,” reads the e-mail. “But only if he turns into a rubber stamp for President Bush’s judicial nominations.”

The e-mail points out that several conservative commentators including Rush Limbaugh and Family Research Council President Tony Perkins have said that much of Frist’s legacy as Majority Leader — and hence his strength heading into the 2008 race — is tied to the eventual outcome of the judges fight.

While the DSCC outright accused Frist of currying favor for 2008 benefits, Senate Minority Leader Harry Reid (Nev.) and Minority Whip Dick Durbin (Ill.) held an impromptu press conference Friday to lash out at Frist’s decision to participate in a teleconference dubbed “Justice Sunday,” run out of Kentucky by a coalition of conservatives accusing Democrats of filibustering judges based on their religious beliefs.

The National Republican Senatorial Committee will strike back today with a 30-second Web ad that unfavorably compares Sens. Edward Kennedy (Mass.) and Robert Byrd (W.Va.) as well as Democratic National Committee Chairman Howard Dean with former Presidents George Washington, Thomas Jefferson and Abraham Lincoln.

“These three trusted the Constitution,” says the ad’s narrator as images of the three former chief executives flash on the screen.

“These three don’t … and they don’t trust the American people that elected a Republican majority,” intones the narrator as images of Kennedy, Byrd and Dean are shown.

Without question, the coming vote on judicial nominations has become a touchstone for conservative activists fed up with the tactics employed by Senate Democrats.

Democrats are currently using the threat of a filibuster to indefinitely postpone votes on 10 of Bush’s judicial nominees.

Frist has been one of the lead voices in support of the “nuclear” or “constitutional” option in which Senate Republicans would ask for a ruling of the chair on whether filibustering judges is unconstitutional. The ruling, which cannot be filibustered, would then be voted on by the full Senate and would need only a simple majority to be sustained.

Democrats see Frist’s high-profile role on judges as part of a continuing pattern of courting conservative voters who will make up a key bloc of the Republican primary electorate in three years.

Reid would not speculate Friday on Frist’s motives regarding judges but did say that conservative activists have influenced the Majority Leader’s thinking in terms of when to actually trigger the floor fight to end judicial filibusters.

Originally, Reid said Frist told him that the battle would not come during this “work period,” referring to the four-week stretch in April before the Senate takes a recess the first week of May. Now, however, as activists have been urging Frist to take the step as soon as possible, Reid believes Frist’s timetable has changed.

“Now I’m getting the idea that he’s getting pressured by all these right-wing groups,” Reid said.

As further evidence of Frist’s move to placate the party’s conservative wing, Democrats point to his role in the recent right-to-die case of Terri Schiavo, a Florida woman who had been in a persistent vegetative state for 15 years.

Frist, a renowned transplant surgeon before coming to the Senate, said that after examining a videotape of Schiavo he believed she had been misdiagnosed. Frist also led the effort within the Senate to allow federal courts to reexamine the case, a measure that passed by unanimous consent.

Legal appeals failed and Schiavo died March 31, two weeks after her feeding tube had been removed.

“Bill Frist needs the support of his party’s right wing if he’s going to get the 2008 nomination,” reads the DSCC e-mail. “That’s why Frist is willing to change the rules of the Senate and force through radical judicial nominees.”

To date, Frist has refused to speculate about his political future once he leaves the Senate in 2006 — in keeping with a two-term limit pledge — but is widely seen as a 2008 candidate.

He has done little to bat down those rumors as he has used his leadership political action committee to line the pockets of various candidates for federal and state office while assembling a top-tier political team to run his largely behind-the-scenes national campaign.

Frist’s office did not return calls seeking comment.

The last Senate Majority Leader to run for president, former Kansas Sen. Bob Dole (R), faced many of the same challenges Frist is currently encountering as he seeks to balance the pressures of serving his conference with his own political ambitions.

Dole resigned from the Senate in June 1996, pledging to “leave behind all the trappings of power, all comfort and all security” to focus full-time on his challenge to then-President Bill Clinton.

Left unsaid in Dole’s farewell remarks was that his connection to Congress — and controversial Speaker Newt Gingrich (R-Ga.) — were hobbling his candidacy.

Dole never recovered from the battering he took during the summer of 1996, losing to Clinton 49 percent to 41 percent.

Paul Kane contributed to this report.