I thought only Republicans did this:
..the five fully identified questioners called on randomly by the president in the East Room were anything but a diverse lot. They included: a member of the pro-Obama Service Employees International Union, a member of the Democratic National Committee who campaigned for Obama among Hispanics during the primary; a former Democratic candidate for Virginia state delegate who endorsed Obama last fall in an op-ed in the Fredericksburg Free Lance-Star; and a Virginia businessman who was a donor to Obama's campaign in 2008..
Actually, the last person I remember doing this was Hillary Clinton. And, if Bush had packed his audience with bonafide backers (which is asserted by WaPo), I think I would have heard about it. I think we'd have all heard about it, every day for the last eight years.