Even as retired Gen. Wesley Clark postponed a planned visit to Capitol Hill this week, his Congressional supporters stood firm behind claims that he would quickly receive upwards of 50 Member endorsements in his nascent Democratic presidential bid.

“I am still comfortable with that number,” said Rep. Marion Berry (D-Ark.), one of the chief advocates for the Clark campaign in Washington. “I have not seen this kind of interest in anything during my time on Capitol Hill.”

The presidential campaign of Rep. Richard Gephardt (D-Mo.) quickly took issue with Berry’s contention of widespread Member support for Clark.

“He has picked up what is consistent with the others [running for president],” said Gephardt senior adviser Steve Elmendorf. “We see no evidence of a big movement to Clark or anyone else.”

Berry said the retired general is eager to hear from Members, but the campaign is so overwhelmed with the demands of getting a head of steam that a visit this week is impossible.

“They are still working 10 people in a twin bed,” Berry said, describing the Clark campaign’s organizational growing pains.

Clark’s visit will be rescheduled for next Tuesday, according to sources familiar with the retired general’s schedule.

Clearly, Clark’s candidacy has roiled the waters of the presidential race both nationally and among Members even as the candidate himself has gotten off to a somewhat uneven start.

Two national polls of Democrats nationally released Monday showed Clark at the top of the 10-candidate field, and his campaign claimed to have raised better than $750,000 in its first 48 hours of existence.

He quickly rounded up 11 Congressional endorsements, a total that includes the entire Arkansas Democratic delegation as well as Ways and Means ranking member Charlie Rangel (N.Y.), Rep. Rahm Emanuel (Ill.), a former top adviser in the Clinton White House, and California Rep. Mike Thompson, a close ally of Minority Leader Nancy Pelosi (Calif.).

“The fact that Charlie Rangel and I are on the same side shows that General Clark is a person who has the ability to work with people from both ends of the spectrum,” explained Thompson, a moderate.

Gephardt still holds a significant lead in the endorsement primary, with 31 Members behind his candidacy, and has focused much more on rounding up support from his colleagues than the other candidates in the presidential field.

Elmendorf said Gephardt has “no worry” that any of his backers will desert him in favor of Clark despite the plaudits paid to the general by Reps. John Tanner (Tenn.) and Ike Skelton (Mo.), both Gephardt supporters.

Sen. John Kerry (Mass.) is second in the endorsement race with 17 Members on board; Sen. Joe Lieberman (Conn.) has 12.

Sens. John Edwards (N.C.) and Bob Graham (Fla.) as well as former Vermont Gov. Howard Dean, former Ambassador Carol Moseley Braun and the Rev. Al Sharpton all have fewer Congressional endorsers than Clark.

There are 167 Democratic House and Senate Members who have not endorsed a candidate — roughly two-thirds of the entire caucus.

Several Members who have offered endorsements cite Clark’s military credentials as the key to their support of his candidacy.

“I’ve always thought that the Democratic Party needs to remind the American people that we are credible and strong on national security issues,” said Rep. Steve Israel (N.Y.). “General Clark has the uniform to prove it.”

Interestingly, Clark has already run into trouble on the campaign trail over his position on the Congressional resolution that allowed President Bush to use force in Iraq.

Late last week, Clark said he would “probably” have voted for the resolution; he recanted a day later, emphasizing that “I would never have voted for this war.”

Thompson, among others, defended Clark’s position on the war and said it would have little effect on his appeal to Members.

“I don’t think there has ever been any question as to where he stood on this resolution,” said Thompson. “I feel extremely confident in his experience militarily along with his world experiences.”

Elmendorf was less charitable about Clark’s explanations.

“I assume he didn’t help himself with his seeming inconsistency on the war,” said Elmendorf.

A Senate leadership aide, speaking on the condition of anonymity, echoed Elmendorf’s comments.

“It’s got to be troubling for the people who have lined up behind him that a former general right out of the gate looks not to be sure-footed on something that should be his issue,” said the aide.

Unbowed by the criticism, Berry expects to convene a meeting of announced Clark supporters to devise a whip strategy shortly.

“The interest is there and it is genuine,” Berry said.

Berry, Rangel and Emanuel are taking the lead roles in reaching out to undecided Members, according to numerous sources. Emanuel did not return calls for comment.

Berry said that it was unlikely that Clark would pick up mass endorsements before he visits Congress, but predicted the backing would come after “everybody gets comfortable” with him.

“If he is only here for one day there will have to be another day” for a large-scale endorsement by multiple Members, Berry indicated.