Actually the worst president in U.S. history is James Buchanan, the Democrat who preceded Abraham Lincoln. However, according to a Quinnipiac University survey, Barack Obama is the worst president since World War II.

Some civil libertarians used to rank George W. Bush as the one of the worst in that area, but by now most agree that Obama is far worse than Bush ever was. His use of drone strikes, using the IRS for political purposes, the many Justice Department abuses, using the NSA the monitor everything everyone does, unconstitutional executive orders and memos to override Congress, appeasing Iran while alienating Israel, supporting the overthrowing of Qaddafi in Libya that led to anarchy and ISIS taking it over (at least parts of it), the refusal to mention Islam or Muslims when talking about Islamic terrorism but instead an eagerness to bash Christians, bad decisions in Syria and Iraq that led to ISIS gaining control over much territory in both of those countries, failure to keep his promise to call the Armenian genocide a genocide instead of a massacre or atrocity, the taxpayer bailout of General Motors, sending weapons to the Mexican drug cartels, etc. Not to mention that under Obama the national debt has increased more that ALL PREVIOUS PRESIDENTS COMBINED -- and he hasn't even finished his second term!