What happened
Hillary Clinton stepped up her attacks on Barack Obama’s experience ahead of Tuesday’s crucial primaries, which include delegate-rich Ohio and Texas. Clinton, whose campaign for the Democratic presidential nomination could hinge on the results, said she is "tested" and "ready," but Obama isn’t. Obama said his positions on foreign policy issues, including his opposition to the Iraq war, showed that he had better judgment than Clinton. "I think the question is, how do you know any president is ready?" Obama said. (ABC News)

What the commentators said
The press has “gone easy” on Obama up so far, said Howard Kurtz in The Washington Post (free registration), but that may be changing as he takes a shot at clinching the nomination on Tuesday. Conservative commentators, “after years of obsessing over Hillary Clinton,” have already started “training their fire on Obama,” giving him his first taste of “the sort of negative onslaught that generally envelops presidential front-runners.” So, “after a year of defying the laws of journalistic gravity, he is being brought back to earth.”

“Obama’s message of hope and his personal charisma” got him this far, said Paul Krugman in The New York Times (free registration). But the growing public enthusiasm for his candidacy—and the expectation among liberals that he “will implement a dramatically progressive agenda”—“rests on surprisingly little evidence.” The real questions will kick in once he secures the nomination and his “honeymoon” with the press ends, as he faces John McCain, “an opponent whom much of the press loves as much as it hates Mrs. Clinton.”

There’s an obvious place to start the digging into Obama’s qualifications, said John Fund in The Wall Street Journal. This week marks the beginning of the money-laundering, fraud, extortion, and bribery trial of Antoin “Tony” Rezko, an old Obama friend and fundraiser. Obama “received little scrutiny as he “rose so quickly in Chicago's famously suspect politics,” but that all may be changing.

Maybe, maybe not, said Robert Novak in the Chicago Sun-Times. “Clinton's operatives have tried frantically, but not effectively, to interest U.S. news media outside Chicago in Obama's possible connection with his home state's latest major scandal”—Obama bought his house on Chicago’s South Side in 2005 on the same day that Rezko’s wife bought the lot nextdoor. The Clinton campaign has “hinted darkly that Obama's past could be used by Republicans when the time came. But these were only hints because of fear that explicit revelations would backfire against Clinton.”