Hillary Clinton is tenacious. Indeed, she is up-to-the-last-possible-moment tenacious.

But she is not politically suicidal.

And she certainly did not want to keep on campaigning for president until the titular leaders of the Democratic party – Democratic National Committee chair Howard Dean, House Speaker Nancy Pelosi and Senate Majority Leader Harry Reid – started screaming: “Enough!”

Since there was a very real possibility that Dean, Pelosi and Reid would have started screaming on this Sunday’s morning talk shows about the absurdity of continuing to campaign after the last primaries, when Barack Obama finally and formally secured enough pledged delegates and super-delegate endorsements to assure that he will be nominated at this summer’s Democratic National Convention in Denver, Clinton has decided to suspend her campaign on Saturday.

After Congressional Democrats made clear to Clinton in a telephone conversation that her time was up – continuing the campaign, said ticked-off New York Congressman Charlie Rangel, is “inconsistent with wanting a Democratic victory” — a chastened campaign communications director Howard Wolfson announced on behalf of the candidate that, “Senator Clinton will be hosting an event in Washington… to thank her supporters and express her support for Senator Obama and party unity.”

Clinton is expected to use the suspension tactic to maintain loose control over her delegates so that she will retain a measure of leverage going into platform debates and some influence over convention planning.

But even her most loyal supporters are saying that it is time for her to accept a supporting role in the 2008 campaign.

And they are not talking about the vice presidency.

While most seriously ridiculous backers – led by former White House aide Lanny Davis and Black Entertainment Television founder Robert Johnson – have launched petition drives designed to pressure Obama to select Clinton as his running mate, cooler heads in the Clinton camp are saying that it is time for the soon-to-be-former candidate and her more wide-eyed supporters that they had better back off.

“There’s no bargaining,” growled Pennsylvania Governor Ed Rendell, a former DNC chair and long-time Clinton backer, who explained to Davis, Johnson and other dead-enders in the Clinton camp: “You don’t bargain with the presidential nominee – even if you’re Hillary Clinton and you have 18 million votes, you don’t bargain.”

Rangel, Clinton’s fellow New Yorker and a key player in the process that made her a senator back in 2000, echoed Rendell’s sentiments.

“You don’t force a candidate,” said Rangel, “and you don’t put him in a position to look like he was forced.”