On the day of the president’s summit on health care reform in February, the Senate Democratic women met, as they routinely do, to discuss Senate business, but as they looked around the room the topic quickly turned to why none of them were with Democratic leaders at the White House.

“There was definitely some anger there,” one Democratic source said.

To be sure, Democratic Conference Secretary Patty Murray (Wash.) had been included in the roster of eight other male Democrats, including Majority Leader Harry Reid (D-Nev.), but the source said rank-and-file women who felt they had been outspoken and “extremely active” in the health care debate felt excluded by the boys-club atmosphere of the Senate and their party. Reid’s office explained that the invite list was limited to leadership, chairmen and Sen. Ron Wyden (D-Ore.), who was invited separately by the White House.

“Murray was there from leadership. No women on the committees [of jurisdiction] were offered a spot,” the source said.

Though women make up a fifth of the Democratic caucus — 13 out of 59 Senators — and chair five committees, many say they still feel as if they are fighting an uphill battle to get the same recognition and respect their male Senate counterparts receive. Female Senators and other Democrats declined to point the finger at any one Member or leader, saying the issue was more systemic and a function of the long-standing, male-centered mentality of the institution.

“I don’t think men recognize that they treat a woman differently and that they accord a different status to their like-self — example, the male as opposed to the female. I’ve fought this all my life,” Intelligence Chairman Dianne Feinstein (D-Calif.) said.

For the Senate women, the issue began to boil again last week during the Democratic chairman’s lunch, when Banking, Housing and Urban Affairs Chairman Chris Dodd (D-Conn.) suggested that new Agriculture, Nutrition and Forestry Chairman Blanche Lincoln’s (D-Ark.) derivatives bill would not be folded into his larger financial reform measure but would have to battle it out on the floor as a stand-alone amendment.

Though Lincoln argued passionately that her bill should not be disadvantaged on the floor, she did not appear to have swayed Reid. Another source said her rant on the subject was off-putting to Reid and male Members. The next day at the party’s regular Thursday lunch, Sen. Maria Cantwell (D-Wash.) stood up and called the leaders out for not showing Lincoln the deference she deserved on the issue. Cantwell specifically noted that she believed Lincoln would be treated better if she were a man, and she pointedly threatened to vote for a GOP filibuster of the broader bill if Lincoln’s measure was not included.

Cantwell this week denied that her primary problem was with the gender politics of the situation. However, she said, “but you need to make sure it isn’t [a problem] either.”

Cantwell “wasn’t the only one” who was concerned about how Lincoln was being treated, Feinstein hinted Tuesday.

Some Democratic aides said Cantwell and other female Senators read too much into Dodd’s and the leaders’ reaction to Lincoln’s bill.

“This wasn’t about disrespect over gender. This is a difference over policy,” one Senate Democratic aide said. “If this were a male chairman, the same thing would have happened.”

Sources on both sides said Lincoln may have overplayed her hand on a derivatives bill that tilted further to the left than either the Democratic leadership or the White House were willing to go. However, female Senators clearly felt that Lincoln was being dealt with in a more dismissive manner than any male chairman would have been.

But other Senate chairmen, male and female, came to Lincoln’s defense and insisted that she be given the respect usually afforded a chairman. That and support in the caucus for her position prompted Dodd to adopt much of her derivatives proposal this weekend.

Sen. Barbara Mikulski (D-Md.) said women do a lot of the work in the Senate and sometimes get “a little sidelined and redlined.” But she noted that being a chairman carries with it automatic stature that male colleagues understand. “What I like is the fact that women are now in charge of committees and therefore we control our destiny when we do that,” she said.

Other examples of Democratic women feeling spurned abound. Cantwell and Sen. Susan Collins (R-Maine) have questioned why the bipartisan climate bill they introduced in December has been virtually ignored, while Democratic leadership and the media focused on talks among three male Senators — John Kerry (D-Mass.), Joe Lieberman (ID-Conn.) and Lindsey Graham (R-S.C.). Before the talks among those three broke down this weekend, they had adopted many key provisions offered by Cantwell and Collins, but the two female Senators said in March that they believed their bill was a better starting point for negotiations.

“I think the bill we came up with is the right approach,” Collins said, according to E&E News PM. “Rather than seeing parts of our bill cannibalized and put into another bill, I think they should take a look at coming onto our legislation.”

Senate Environment and Public Works Chairman Barbara Boxer (D-Calif.) provided another prime example last year of the sensitivity some female Senators have about whether they are treated similarly to their male counterparts.

During a hearing in her committee in July, Boxer told a testifying brigadier general to stop calling her “ma’am.”

“Could you say ‘Senator’ instead of ‘ma’am’?” she asked. Boxer continued, “It’s just a thing, I worked so hard to get that title, so I’d appreciate it, yes, thank you.”

Murray, the No. 4 Democratic leader, acknowledged that in the past women were promoted to Senate leadership to provide a “token” female voice, but were rarely listened to. But she said that is no longer the case.

“When I came, I often was the only woman in the room and now there’s more than one. And things have changed a lot in that respect. We had to fight really hard for the respect of men, and I think the respect is there now,” Murray said.

Without directly referencing the recent controversy over Lincoln, she added, “I think tensions arise between committee chairs all the time, and now we have women that have risen to committee chairs.”

Several Democrats said Murray has positioned herself well in leadership, because she knows how to navigate the sometimes murky relationships with the other leaders — all of whom are men — and because she has become a trusted, reasoned voice in their meetings.

Still, some Democrats said that at internal meetings of leaders, chairmen or other working groups, they have witnessed episodes in which a woman’s idea is dismissed at first until a male Member of the group voices a similar opinion.

Feinstein did not speak that point, but said the bias is “subtle, and … it’s really hard to describe, but there still is some of it, yes.”