What the hell is wrong with Kent Conrad and Max Baucus?

Apparently you can get these two "moderate" Democrats to jump through hoops merely by calling the president a liar during a joint session of Congress. From Time:

The controversy over Republican Representative Joe Wilson's shouting "You lie!" at the President over his claim that illegal immigrants wouldn't benefit from health-care reform apparently sparked some reconsideration of the relevant language. "We really thought we'd resolved this question of people who are here illegally, but as we reflected on the President's speech last night, we wanted to go back and drill down again," said Senator Kent Conrad, one of the Democrats in the talks after a meeting Thursday morning. Later that afternoon, Baucus said the group would add a proof-of-citizenship requirement for participation in the new health exchange — a move likely to inflame the left.

If the article has characterized this correctly, Baucus and Conrad's response to Wilson's baseless charge about the bill's treatment of illegal immigrants caused them to go back and eliminate coverage for legal immigrants. Who are they trying to appease with this change? Even Wilson doesn't seem to object to legal immigrants receiving subsidies.