Sen. McCain Acting as One of Obama's Key Allies

Making Sen. Graham (R-S.C.) a little nervous

President Barack Obama has an important new ally as emboldened Republicans work to derail his agenda: John McCain.

The shift is striking: The 2008 rivals never got along throughout Obama's first term in office. McCain has been Obama's chief tormentor on issues ranging from the budget to Benghazi, tartly saying in late 2010 that the two men had "no relationship."