Editor's note: This is the third report in a three-part series investigating the role of congressional caucuses and the special interests that seek to influence them

Members of the Congressional Black Caucus (search) say they are "the conscience of the Congress," and have used the moniker most recently to explain the group's opposition to war in Iraq and the cost of its aftermath.

"The Bush administration had not presented us with the evidence that we needed — both constitutionally and morally — to support its plans," CBC Chairman Rep. Elijah Cummings (search) said in September when he spoke for the entire caucus to explain why the group's 39 members voted en masse against President Bush's emergency request for $87 billion for military costs and reconstruction efforts in Iraq and Afghanistan.

"It has not done so, I must note, to this day," Cummings, D-Md., added.

In a Congress that is nearly 200-caucuses strong, the CBC is like all the rest in that it was formed around common interests. However, it has the distinction of being the best funded and among the first to emerge.

Formed in 1969 by the 13 black members then serving in Congress, the caucus' goal is "to positively influence the course of events pertinent to African-Americans and others of similar experience and situation, and to achieve greater equality for persons of African descent in the design and content of domestic and international programs and services."

Currently representing 22 states, the CBC continues to weigh in mostly on civil rights and domestic issues relating to health care, education and labor. Besides race issues, members are bound by their generally left-of-center politics and consistency in voting Democrat.

"The black caucus was founded at a time when there weren't many blacks in Congress — and there is still a disproportionate number. This gave them a collective effort and they've been able to do good work," said former Minnesota Rep. Bill Frenzel, who served 20 years in Congress and is now a fellow at the Brookings Institution (search).

CBC members cite as a recent victory their influence in persuading Senate Democrats to stall judicial nominees like Mississippi judge Charles Pickering (search). They are also actively opposing the nomination of African-American California Supreme Court Justice Janice Rogers Brown (search), whom they say is too temperamental and unqualified to serve on the U.S. Court of Appeals for the D.C. Circuit.

Earlier this year, the CBC filed a friend of the court brief in favor of the affirmative action policy at the University of Michigan Law School. The policy was upheld by the U.S. Supreme Court.

"We still believe that there are challenges that exist in the 21st century," said CBC spokesman Paul Brathwaite, who emphasized the group's focus on civil rights, affirmative action, disproportionate levels of poverty and unemployment among black families.

But some are quick to point out that as strong and resourceful as the CBC is, it does not represent all blacks.

"They are not the only ones," said Alvin Williams, President and CEO of the conservative-leaning Black America's Political Action Committee (search). BAMPAC finances black candidates who support school vouchers and privatizing Social Security and oppose abortion rights — all positions antithetical to the CBC.

"We're for having input from all angles. Now it's just woefully imbalanced," Williams said.

The CBC is backed by a powerful non-profit arm, the Congressional Black Caucus Foundation, which according to public Internal Revenue Service figures, raised $7 million in 2002, more than any other caucus-related foundation or institution currently operating.

Much of the foundation's money goes to annual conferences, seminars, scholarship programs and public health and home ownership initiatives. It also gets support from heavy hitters in the business community like State Farm, Miller Brewing, and Pfizer, all represented on the CBC Foundation's Corporate Advisory Board.

While the CBC is the oldest and best-funded caucus founded on shared racial or ethnic concerns, the Congressional Hispanic Caucus (search) is not far behind as one of the most influential.

The caucus, formed in 1976 by the five Hispanic members then serving in Congress, now has 20 members and its own separate foundation, which raised $2.3 million in 2001.

Like the CBC, its members are all Democrats and share many of the CBC's positions. Most recently, the two caucuses announced that along with the Congressional Native American Caucus, the Asian Pacific American Caucus and other House Democratic members that they are backing a bill that would increase health care access to minorities.

Chairman Ciro Rodriguez, D-Texas, said the Hispanic caucus has been instrumental in getting to the table issues that are both uniquely important to Hispanics as well as to the nation as large.

"[Hispanics] have played a significant role in this country, not only in defending this country, but participating in the development of this country," Rodriguez told Foxnews.com. "Of course, we'd like to have more influence, but we're getting there."

Immigration issues, education, civil rights and integrating Hispanics in arts and entertainment top their list of recent activities, Rodriguez said.

The Hispanic caucus hasn't taken a strong stand against the war, but it has actively worked to defeat President Bush's judicial nominees, including the first Hispanic nominated to the D.C. Circuit Court, Miguel Estrada (search), who dropped out of the running after a two-year Senate stalemate.

Like the CBC, the Hispanic caucus has its detractors. In March, six Hispanic members of Congress — all Republican — formed the Hispanic Conference (search) to combat what they say is an imbalance in representation in their own ranks.

"Today we introduce a group who will look out for the best interests of all Hispanics — not just those with liberal politics," said Rep. Henry Bonilla, R-Texas, at the group's inception. Florida Rep. Ileana Ros Lehtinen chairs the group.

While ethnic and racial caucuses have proven a major force on Capitol Hill, the growing diversity among Hispanic voters — demonstrated by the formation of the Hispanic Conference — may prove advantageous to Hispanics in the long run, said Larry Sabato, director of University of Virginia's Center for Politics (search).

"It used to be that Hispanics were as Democrat as African-Americans, but they are becoming more diverse. That means they have a strong foothold in both parties and therefore are more listened to," Sabato said.

The CBC, on the other hand, might be putting itself at a disadvantage by being so heavily partisan, Sabato suggested.

"African-Americans are so overwhelmingly Democratic that when Republicans are in charge of both houses of Congress, they have no reason to listen to them."