"Obama failed to close Guantanamo Bay as promised. He continued warrantless surveillance and military tribunals that denied defendants basic rights. He asserted the right to kill U.S. citizens he views as terrorists. His administration has fought to block dozens of public-interest lawsuits challenging privacy violations and presidential abuses….
"As Obama and Atty. Gen. Eric H. Holder Jr. have admitted, waterboarding is clearly torture and has been long defined as such by both international and U.S. courts. It is not only a crime but a war crime. By blocking the investigation and prosecution of those responsible for torture, Obama violated international law and reinforced other countries in refusing investigation of their own alleged war crimes. The administration magnified the damage by blocking efforts of other countries like Spain from investigating our alleged war crimes."
See also Turley's recent NPR interview, in which he rebuts some of the common rationalizations for Obama's policies (such as: he's privy to information we don't have, or the Republicans would be worse).
Paralleling Turley's argument, Obama has dramatically accelerated deportations of undocumented immigrants over and beyond President Bush's record.
I don't think the point of all this is that Obama is "worse" than Bush, or even that there is no difference between Republicans and Democrats on civil liberties. Rather, the two major parties have slightly different roles to play in the same oppressive system. Often (but not always!) Republicans are more aggressive than Democrats in expanding state repression. But just as often Democrats are the collaborators and consolidators -- and the ones who coopt and defuse most opposition from the left. The growth of state repression in the U.S. is a structural change that goes beyond party politics, and won't be solved by voting this or that official out of office.