By Mark Willen, Senior Political Editor April 15, 2008 Political reporters have probably described each of the 20 Democratic debates as the most important so far, but when Hillary Clinton and Barack Obama face off tomorrow night in Philadelphia on ABC, it will really be true. Honest. It's been 49 days since the last debate (just in case you weren't counting) -- long enough for Clinton to rebuff calls that she quit the race, for the Rev. Wright's comments and Obama's speech on race to have settled in, for Clinton to defend and then take back her sniper-fire stories, for Bill Clinton to prove inept in defending his wife (again), and for Obama to put his foot in his mouth (big time) with talk of voters who turn to religion and guns out of bitterness. Now the fun starts. Though Obama has been on the defensive for days, the real pressure tomorrow will be on Clinton, who has to walk a fine line if she's to get the big win she must have in Pensylvania next week. She's been on the attack over Obama's huge mistake and obviously feels she's scoring points. But it's one thing to attack Obama when she's on the stump and quite another when he's sitting next to her. He'll get a chance to respond, and presumably by now he's thought up a better explanation than he's offered so far. He may never be able to explain away linking religion to bitterness, but he can put a big dent in Clinton's attacks by adding context, explaining that many voters have every reason to be bitter and by putting the elitism charge to rest once and for all. He can ask, for example, how a couple that made $100 million in the last seven years gets off calling someone who grew up without a father and whose mother relied on food stamps to get by an elitist. Advertisement What's more, if Obama sticks to the high road and Clinton keeps punching, she risks going too far, turning off voters who really think it's time to get beyond negative politics and phony labels. Voters want the candidates to address the issues, and the real winner tomorrow will be the one who puts forth a detailed and convincing plan for dealing with the economic realities that are holding Pennsylvania back -- the net loss of jobs, the housing crisis, the credit markets, the deterioriation of cities, schools that don't teach and health care that's unaffordable. That's what voters want to hear -- not more name calling. What do you think the chances are they'll get it?