According to the Library of Congress, the Constitution provides the origination requirement for revenue bills, whereas tradition provides the origination requirement for appropriation bills. See Sullivan, John. "How Our Laws Are Made (页面存档备份,存于互联网档案馆)", Library of Congress (accessed August 26, 2013).
Maine Independent Angus King To Caucus With Senate Democrats. (页面存档备份,存于互联网档案馆) "Angus King of Maine, who cruised to victory last week running as an independent, said Wednesday that he will caucus with Senate Democrats. [...] The Senate's other independent, Bernie Sanders of Vermont, also caucuses with the Democrats."Politico. 2012-11-14. Retrieved 2020-11-28.
Maine Independent Angus King To Caucus With Senate Democrats. (页面存档备份,存于互联网档案馆) "Angus King of Maine, who cruised to victory last week running as an independent, said Wednesday that he will caucus with Senate Democrats. [...] The Senate's other independent, Bernie Sanders of Vermont, also caucuses with the Democrats."Politico. 2012-11-14. Retrieved 2020-11-28.
According to the Library of Congress, the Constitution provides the origination requirement for revenue bills, whereas tradition provides the origination requirement for appropriation bills. See Sullivan, John. "How Our Laws Are Made (页面存档备份,存于互联网档案馆)", Library of Congress (accessed August 26, 2013).