He’s done just enough to earn credit for trying harder than any other Democratic president to tackle the issue, but he has yet to throw the full weight of his office or his formidable campaign operation behind it. His best chance will come early in his second term as lawmakers confront a series of budget battles, but Obama appears more ready to spend his political capital on guns, immigration and climate change.

The president has never precisely defined what hard choices he would be willing to make on Medicare and Social Security. It’s not even clear what he would do if he had the power to remake the programs on his own, without worrying about opposition from Republicans or Democrats.

And though Obama has talked about shared sacrifice from both parties, he has not gotten to the point in deficit negotiations at which he’s had to pressure rank-and-file Democratic lawmakers to cross their red line on the sacred issues, as House Speaker John Boehner (R-Ohio) did with his own party in raising taxes.

Unless Obama seizes the opportunity in the next few months, entitlement reform will hang over his second term, lurking like a legacy-killer if he hands off the task to the next president, deficit hawks warn.