Superdelegates to the Democratic presidential nominating convention probably aren’t feeling very super right about now. Squeezed is more like it, as pressure mounts from candidates and their supporters to commit to a candidate or even switch their votes right now instead of waiting until the party's convention in August.

As senators Barack Obama and Hillary Clinton vie in what have been billed as decisive primaries, the superdelegate count could be the deciding factor if the nomination isn’t secured by either Tuesday night.

There are 370 Democratic delegates at stake in four states -- Texas, Ohio, Rhode Island and Vermont -- but the party's system of awarding delegates proportionally will make it tough for either candidate to post big gains.

The biggest prize is Texas, with 193 delegates, where the Democrats will have a primary and a caucus. The primary will determine 126 delegates, based on voting in 31 individual state senate districts. The caucuses will determine 67 delegates. They will be awarded based on the statewide results of the caucuses, which will be held after the primary polls close.

The two-step system increases the possibility that the primary winner might not win the most delegates to the party's national convention this summer.

Ohio will have 141 Democratic delegates available, with 92 based on voting in 18 congressional districts, and 49 based on statewide results. Late returns in some areas, particularly Cuyahoga County in northeast Ohio, could delay the awarding of some delegates.

Rhode Island will have 21 Democratic delegates at stake and Vermont 15.

With all that complicated math, the one thing both campaigns know for sure is that if the race is close, superdelegates could make the difference.

Arguably, the heat is strongest under the 42 members of the Congressional Black Caucus, which is leaning ever so slightly toward Obama. At the end of January, the CBC was evenly split between the candidates. Last week, the deadlock was broken when Rep. John Lewis, (D-Ga.), who had announced his support early on for Clinton, said he would now support Obama.

Lewis, a civil rights icon who marched with the Rev. Martin Luther King, Jr., was pressured by pro-Obama colleagues and bloggers and voters in his district who largely support the Illinois senator.

Superdelegates -- party leaders and elected official delegates -- constitute about a fifth of all delegates who vote for a nominee at the convention. They are unpledged delegates who are free to support whomever they choose. There were 796 superdelegates until Rep. Tom Lantos (D-Calif.) died on Feb. 11, leaving 795 superdelegates at stake.

Clinton's husband, former President Bill Clinton, who also is a superdelegate, has asserted that his wife must win both Texas and Ohio to keep her campaign alive. On Friday, Hillary Clinton's advisers attemped to recast the stakes, saying if Obama lost any of the four presidential primaries Tuesday, it would show Democrats are having second thoughts about him.

Clinton is trying to slow down the momentum of Obama, who won 11 straight primaries and caucuses since Super Tuesday on Feb. 5. Obama has 1,187 pledged delegates to Clinton’s 1,035.

Clinton still leads among superdelegates, according to the AP survey. But her total is down two in the past three weeks, with defections to Obama. None of Obama's has publicly strayed, according to the AP tally.

In the event of a close or contested convention among the pledged delegates, Clinton supporters believe superdelegates would give her the nomination.

Some observers, including some Obama supporters, have argued that it would be unfair and thwart the will of the people if superdelegates vote to give Clinton the nomination if Obama has a solid lead going into the convention.

“Our basic belief is that voters should be determining who the nominee is, who the president is,” said James Rucker, cofounder of ChangeofColor.org, an organization that seeks to invigorate black politics and black politicians.

Last week, the site launched a petition drive to pressure pro-Clinton CBC members to vote for the candidate their districts or states have supported.

The Clinton camp has set up a Web site called Delegate HUB, which features columns and blogs that argue the Clinton view of issues, calls Obama's positions and judgments into question and emphasizes reasons why superdelegates are supporting Clinton.

Rucker told BlackAmericaWeb.com his organization is not advocating for Obama or Clinton, but that public officials -- particularly black public officials who generally represent majority black districts -- should vote as their constituents have.

“It’s critical for the sake of integrity for the Congressional Black Caucus,” Rucker said. “We as black folks need to feel we can believe in these folks when they function as a body.”

Rep. Stephanie Tubbs Jones (D-Ohio), a Clinton supporter, has denounced the kind of pressure that she and other Clinton backers, including Rep. Sheila Jackson Lee (D-Texas) and Rep. Maxine Waters (D-Calif.), have endured.

“I am proud to be a Hillary Clinton supporter,” Tubbs Jones told CNN Monday. “I am going to be with her until she says ‘Stephanie, I am getting out.’ In politics, all you have is your word. There is integrity and loyalty. Shame to those people who put pressure on a man who got beat on the head for taking a stand.”

Lewis, in announcing his switch to Obama last week, said the decision was more difficult than his decision to participate in the bloody march from Selma to Montgomery, Alabama in 1965, a protest in which he was nearly beaten to death.

But in a statement, Lewis also described Obama’s campaign as “the beginning of a new movement in American political history,” maintaining that he wanted “to be on the side of the people.”

“I think that’s a great political answer,” Rucker said of Tubbs Jones’ loyalty argument. “Who is her loyalty greater for: Her loyalty to Senator Clinton or her loyalty to the people who put her in office?

“You can promise Hillary Clinton you will support her. You can campaign for her. That makes complete sense. But when it comes to using your position to override the will of the voters, then that was a promise she shouldn’t have made.”

That said, however, Rucker said ChangeofColor.org was not advocating that those CBC members who go against their constituents at the convention be defeated themselves at the polls in November.

“I don’t believe this issue along -- betraying the votes of one’s constituents -- would have the ColorofChange going after someone. We have not brought that up on our site at this point, but voters have brought it up,” Rucker said.

David Bositis, senior researcher at the Joint Center for Political and Economic Studies, said this debate all could be moot with the momentum that Obama currently enjoys.

If Obama goes to the convention with a convincing lead in pledged delegates, then everyone else will likely fall in line. In that case, Bositis told BlackAmericaWeb.com, the superdelegates become a non-issue.

“Obama’s winning,” Bositis said. “Right now, I just don’t see it turning around.”