If wins in either Indiana or North Carolina Tuesday, the primary election terrain suddenly begins to look more favorable to her than at any other point since Super Tuesday Feb. 5.
For the first time since February, she will enter a month-long stretch of states where a variety of factors leave her well-positioned to win or compete in most of them.
None of the remaining six states hold caucuses, the nominating events where 's campaign's organizational strength and savvy shines. Four of the six are closed primaries, which neutralizes Obama's strength among independents and Republicans. None have African-American populations above 10 percent - a key Obama constituency. And two rank among the top 10 states with populations aged 65 or older - a group Clinton runs well with.
Regardless of her performance against Barack Obama in the six remaining primaries, the delegate math remains daunting for Clinton. But if her campaign gains momentum out of Tuesday's primaries, the next six contests in West Virginia, Kentucky, Oregon, Puerto Rico, Montana and South Dakota may afford enough opportunities for victory to sustain her campaign at least through June 3.
"After Tuesday, most of the upcoming states are really good states for her," said Tad Devine, a strategist for 2004 Democratic nominee John F. Kerry. "She's got some good real estate in front of her."
For Clinton, the run of competitive states is a welcome reprieve after a post-Super Tuesday gauntlet peppered with states that played to Obama's strengths. When Clinton finally broke Obama's winning streak on March 4, her wins in Ohio, Texas and Rhode Island were quickly countered four days later by a landslide caucus loss in Wyoming followed by another landslide primary loss March 11 in heavily African-American Mississippi. Then came six weeks with no contests between Mississippi and Pennsylvania on April 22.
The final stretch of six states begins with the May 13 West Virginia primary, where the few available polls show her with a comfortable lead. Obama has backing from Sen. Jay Rockefeller and Rep. Nick Rahall but much of the state political establishment has yet to pick a side.
The signs are promising for the Clinton campaign: She has carried Appalachia to date and only Florida and Pennsylvania have a higher percentage of residents over the age of 65. In an ominous note, a Rasmussen Reports state poll released Sunday reported 57 percent said it was very likely or somewhat likely that Obama shares some of controversial Rev. Jeremiah Wright's views about the United States.
Kentucky, another Appalachian state where Clinton holds a commanding lead in the polls, weighs in one week later on May 20. If, as expected, she captures Kentucky, she'll be able to better weather a likely loss in Oregon, where she trails in the polls with little likelihood of catching the better-organized Obama.
As of May 2, Obama had put up $450,000 in ads on commercial television and cable in the Portland market compared to about $101,000, said Mark Wiener, a Portland-based Democratic consultant.
"I think it should be a pretty solid state for Obama," said Wiener. "it's sort of Pennsylvania in reverse-it's not a question of whether he's going to win, but by how much, and can she win enough of the vote to score some kind of moral victory?"
Less than two weeks later, on June 1, Puerto Rico will vote. While Clinton was at first expected to have a significant advantage-she represents the state with the largest Puerto Rican population-Obama managed to win the endorsement of Governor Anibal Acevedo Vila and several other high-profile leaders.
Byzantine local politics clouds the campaign on the island but Clinton has shown an ability to win congressional districts in New York and Florida with high concentrations of Puerto Ricans.
The final states to vote are Montana and South Dakota on June 3. Obama has carried every state that borders the two-but every single one of them held caucus events. With no major metropolitan areas and African-American populations of less than one percent in both states, the Clinton campaign will have no excuses for losing.
Either way, given Obama's delegate lead, a strong finish still may not be enough to alter the outcome.
"If you're fading at the tape and you win, you still win the horse race," says Carter Eskew, a Democratic consultant.
By Charles Mahtesian and David Mark