WASHINGTON -- Senate Finance Committee Chairman Max Baucus on Tuesday indicated that President Barack Obama may be warming to the idea of taxing employer-provided health-care benefits to pay for an overhaul of the nation's health system. But the White House, and a key Democratic senator, quickly shot down the idea that the president has had a change of heart.

Mr. Obama met with 24 Democratic senators at the White House Tuesday afternoon to talk about legislation they are crafting to overhaul the nation's...