The latest question for the Democratic Party is whether its presumptive nominee, Sen. Barack Obama, has given the Clintons too large a role in next week's national convention.

While Sen. Hillary Rodham Clinton and her husband, former President Bill Clinton, correctly ceded the race for the nomination to Mr. Obama and pledged to work for his victory in November, there is suspicion and uncertainty about what the Clintons are up to.

Mr. Obama, nevertheless, is playing the matter correctly. In quest of Mrs. Clinton's supporters, who potentially are more attached to her than to the Democratic Party, he is giving both Clintons maximum exposure at the party's signature event. This is not unprecedented. Mr. Clinton, after all, is a former two-term Democratic president, the last since Franklin Delano Roosevelt. Allowing the name of a rival defeated in the primaries to be put into nomination is also not new and can serve as a way to forge party unity around the chosen candidate.

Mr. Obama, in his treatment of the Clintons, is showing generosity consistent with his pledge to bring Americans together. In doing so he is also laying down a marker that says to the Clintons and the party that if during the campaign they undercut him, or do not work sincerely for his election, a Democratic loss in November will lie on their heads.

Prominent play at the convention for the ambitious Clintons constitutes a gamble for Mr. Obama. If they respond to his openhandedness in good faith, he should have more support from the Democrats' core constituency than he would have otherwise. If the Clintons try to double-cross him, failure at the polls for the party will be due, at least partly, to them. Should that occur, the chances that Mrs. Clinton might have for the Democratic nomination in 2012, which some feel is the Clintons' real goal, would be dead.

One has to assume that Mr. Obama and his political strategists know what they are doing as they construct the convention scenario. Mrs. Clinton was already late and ungenerous in letting go of her primary run. She needs to play it straight from now on by demonstrating unconditional support for her party's nominee.

Generosity on Mr. Obama's part is not only right, but also smart.