If Mitt Romney wins the 2012 GOP nomination, Democrats could learn a lesson from the way Ted Kennedy ran against Romney in 1994.

Salon.com says that Kennedy decided to make Romney's religion the subject of negative attacks, and it clearly didn't work. The press treated Romney sympathetically, and the issue became a huge distraction for the Kennedy campaign. Eventually Kennedy dropped religion as an issue and focused their attacks on Romney's work with Bain Capital.

Salon's Steve Kornacki says the past could prove instructive.

Granted, the way Joe Kennedy went about making the Mormon church’s social conservatism an issue was particularly blunt and inartful. Presumably, the Obama campaign could find a craftier way to do it, raising questions about Romney’s own actions without having it seem like an assault on his church. But the real lesson of Kennedy’s botched attack is probably that the intersection of personal faith and politics is a dangerous place to wage a negative campaign. So for the Obama campaign, the question to consider might be: Why even go down that road — especially when there’s ample material to attack Romney on that has nothing to do with religion?