Presidential candidates barely paused for breath after Super Tuesday before plunging ahead with the next phase of their campaigns.

With good reason. For Democrats Hillary Clinton and Barack Obama, it is increasingly clear that every single delegate matters.

So convoluted are the Democrats' delegate-allocation formulas that no one could say for certain Wednesday who has the lead. Some sources had Obama four or five delegates ahead; others had Clinton in front by as many as two dozen.

Suffice it to say that both are bracing for a protracted nomination fight.

Matters are simpler on the Republican side, where John McCain has the race well in hand. Paul Green, director of the Institute for Politics at Roosevelt University Chicago/Shaumburg, said McCain's main job now is simply to "make sure he doesn't make any mistakes."

For the Democrats, money suddenly has become a factor. Clinton announced Wednesday that she is lending her campaign $5 million. This followed word that she raised $13.5 million in January, far short of Obama's $32 million take.

"She's got a double hit facing her," Green said of Clinton. "A money problem, coming as the next primary and caucus dates all seem to favor Obama."

Indeed, three of the next four Democratic contests are caucuses: Nebraska, Washington and Maine. The format seems suited to Obama's strengths; he's won seven of eight caucuses conducted so far. A primary in Louisiana, with blacks constituting nearly one-third of the population, is also up next on the Democratic calendar.

While Clinton is popular among blacks, their actual votes have swung heavily to Obama. An Associated Press exit poll had the Illinois senator winning eight of every 10 black votes on Super Tuesday.

As for the challenges he faces, Obama will be seeking ways to cut into Clinton's strong support among women, Latinos and older voters.

Clinton's advantage among Hispanic voters was on display Tuesday, and not only in the border states of California and Arizona. Even, in Illinois, where Obama won with nearly 65 percent of the vote, there are strong indications the Chicago native may be having trouble reaching Hispanic voters.

While he did well in heavily Hispanic suburbs like Aurora, he lost predominately Hispanic wards in his hometown.

In fact, of the 14 Chicago wards Obama lost Tuesday, at least 11 have significant Hispanic populations. More importantly, it appears Obama did not carry any Chicago wards that had a majority of Hispanic voters.

That could be a significant advantage for Clinton in Texas, the largest state still to vote.

Obama also will be seeking ways to attract older voters.

Gerald Rosenberg, an associate professor of political science at the University of Chicago, speculates that older voters, who grew up in a different era of race relations, might be slower to embrace a black candidate.

Or, he said, older Americans might be more skeptical that Obama can deliver on his promises of change.

"Hope is lovely," Rosenberg said, "but they want their Medicare."

Among remaining Republicans, many analysts think time is running out quickly for Romney. Why has his campaign failed to gain traction, particularly when many conservatives want an alternative to McCain?

Rosenberg thinks voters perceive too many discrepancies between his resume and campaign rhetoric.

"He was a moderate governor of Massachusetts," Rosenberg said. "He has tried to reinvent himself, and he's done it with his own money. That just doesn't fly; he's not that conservative."

Former Arkansas Gov. Mike Huckabee enjoyed a strong Super Tuesday showing, winning five southern states. Green says Huckabee will continue to be a "player" below the Mason-Dixon line.

The question is whether enough strictly southern states remain to give Huckabee much additional boost. Besides Louisiana, there's Virginia, Mississippi, North Carolina and Kentucky.

Rosenberg agrees with Green that McCain can hardly lose the nomination at this juncture. So secure is his lead that he might not even need to drift much to the right -- thereby possibly risking his popularity among independents -- in order to soothe discontented conservatives.

"If he starts to waffle, that would be political suicide," Green said.