Democratic presidential candidate Barack Obama is leveling harsher attacks on rival Hillary Clinton, arguing Clinton hasn’t leveled with the American people about what she’d do as president.

During an event in Des Moines early Saturday afternoon, Obama accused Clinton of repeatedly sidestepping questions about Social Security because it’s a hot-button issue. "You might remember that this came up in the last presidential debate and when Senator Clinton was asked about it, she wouldn’t say what she thought needed to be done," Obama said.

While Obama said Clinton wasn’t alone in "ducking" questions about Social Security’s long-term financial health, Obama pointedly attacked Clinton’s campaign claim that she is "ready to lead" the country.

"A candidate for president owes it to the American people to tell us where they stand because you’re not ready to lead if you can’t tell us where you’re going," Obama told the crowd of about a hundred people gathered at a senior center.

Obama favors raising the payroll taxes that finance Social Security so wealthy Americans — who aren’t today taxed on income above the level of $97,500 — pay more into the Social Security system. "The underlying system is sound. The actual problem is a projected cash shortfall problem that can be readily solved," Obama said. "But the longer we wait to solve the problem, the bigger it grows."

Obama’s campaign had Tod Bowman, a teacher at Maquoketa High School, speak to the crowd first. "I was at a forum with Senator Clinton and had the chance to ask her what she would do to protect Social Security," Bowman said. "She gave a lengthy response that didn’t answer my question and I got the feeling that she really didn’t want to answer my question."

The Clinton campaign, in turn, is accusing Obama of reversing course on Social Security, arguing a few months ago Obama said "everything was on the table, including raising the retirement age." Mark Daley, an Iowa-based spokesman for Senator Clinton, said Clinton has been "clear" about her approach to dealing with Social Security and has said she wants a bipartisan approach that would not include the private accounts President Bush has pushed.

Click on the audio link below to listen to Bowman’s brief remarks, then Obama’s speech in Des Moines.

AUDIO: Obama in DSM (mp3 runs 14 min)

Radio Iowa