Donald Trump accused the Clinton campaign of of being the original source of the 'birther' controversy, which held that Barack Obama was not born in the United States. Although the Clinton campaign has forcefully denied their involvement in pushing the controversy, the Obama campaign itself accused Clinton of "dirty tricks" during the 2008 primary.
The initial controversy arose when the Clinton campaign was accused of circulating this photo of Obama dressed in traditional African garb:
Barack Obama's campaign team today accused Hillary Clinton's beleaguered staff of mounting a desperate dirty tricks operation by circulating a picture of him in African dress, feeding into false claims on US websites that he is a Muslim.
Obama's campaign manager, David Plouffe, described it as "the most shameful, offensive fear-mongering we've seen from either party in this election". Obama has had to spend much of the campaign stressing he is a Christian not a Muslim and did not study at a madrassa.
This isn't the only evidence to suggests the Clinton campaign was behind many of the questions about Obama's origins.
Clinton's 2007 campaign manager Mark Penn circulated a campaign strategy memo in which he suggested attacking Obama for not being "fundamentally American" and targeting then Senator Obama's "lack of American roots."