McCain also harshly criticized Obama for scrapping construction of the U.S. missile defense complex in Poland, declined to enter negotiations over climate change legislation similar to what he had proposed in the past, and strongly opposed the Obama health care plan. McCain led a successful filibuster of a measure that would allow repeal of the military's "Don't ask, don't tell" policy towards gays. Factors involved in McCain's new direction included Senate staffers leaving, a renewed concern over national debt levels and the scope of federal government, a possible Republican primary challenge from conservatives in 2010, and McCain's campaign edge being slow to wear off. As one longtime McCain advisor said, "A lot of people, including me, thought he might be the Republican building bridges to the Obama Administration. But he's been more like the guy blowing up the bridges."