Joe Lieberman is up to his old tricks again. The Connecticut senator threatened Sunday to oppose the health-care bill if it allows uninsured people as young as 55 to purchase Medicare. Democratic aides also said that Lieberman told Senate Majority Leader Harry Reid that he would join a Republican-led filibuster against the bill. Lieberman could provide the 60th crucial vote needed to end debate on the measure, and Reid has been counting on his support. Appearing on CBS, Lieberman said, “Though I don’t know exactly what’s in it, from what I hear, I certainly would have a hard time voting for it because it has some of the same infirmities that the public option did.” Lieberman says he opposes the added costs to taxpayers and increase to the deficit, though the CBO is expected to announce that the Medicare buy-in would be deficit neutral.