Barack Obama has overtaken Hillary Clinton as the most probable nominee of the Democratic Party to run for the US presidency in the November 2008 election. But probable does not mean inevitable.
After Hillary Clinton's losses to Obama on Tuesday in Maryland, DC, and Virginia, a consensus emerges that Hillary Clinton must win Ohio and Texas on March 4. But the real question for Democrats in early March won't be who won Texas: the do-or-die state for Hillary's candidacy is Ohio.
Ohio votes neither Democtatic (Blue) nor Republican (Red) in federal elections with any consistency. It is an unpredictable "swing state" or "purple state." It's the state that gave George W. Bush the presidency in 2004.* Other purple states include Florida, Nevada, New Mexico, Arkansas, Tennessee, and Louisiana.
Red states almost always go to Republicans, blue to Democrats. If a presidential candidate shows he or she can win purple states, it puts him or her in good stead to win the election. The US presidency is not awarded to the candidate who gets the majority of the popular vote overall, it goes to whoever wins the most states' delegates.** And in most states, winning a majority of the popular vote wins you all of that states' delegates (Big states have more delegates than small states). The delegates meet after the election in something called "the Electoral College" to formally tally up the count.
And if Hillary does not win Ohio, her chances of winning a general election look slimmer. That's a fact no Democrat will be able to deny, and Barack Obama will appear the more electable candidate. If Hillary should lose Ohio, the nomination of Barack Obama as the Democratic Party candidate for president will be almost inevitable.
* The Republican Party of George W. Bush may well have stolen the election of 2004 by rigging the vote in Ohio. But the potential for vote rigging aside, Ohio can -- in theory -- go either way.
** In 2000, Gore got more votes than Bush. Gore won the popular vote but lost in the delegate count. That's because the vote was close in Florida and the US Supreme Court intervened, awarding the purple state of Florida to Bush. It has been proven that Gore actually won Florida in 2000, but in this Republican Party controlled state -- Florida's governor is the presidents' brother -- the names of many Democratic-leaning voters were taken off the voters lists.