On July 29, 2004, Sen. John Kerry, D-Mass., came out of the Democratic National Convention with a slight lead over President George W. Bush in national presidential polls. But throughout the month of August he was put on the defensive by ads released by the Swift Boat Veterans for Truth, who questioned his military record in Vietnam. By the time Bush accepted the Republican nomination in early September, Kerry had relinquished the lead, and he would never regain it.

Without relitigating the 2004 election or revisiting the Swift Boat issue, it’s worth questioning whether we could be seeing a repeat of this episode in the current election, with President Obama unleashing a wave of attacks against presumptive Republican nominee Mitt Romney’s business career at Bain Capital.