8. George W. Bush
Climbing to the nation's highest office after overseeing more lethal injections than any other Texas governor in history, before or since, Bush soon made a name for himself by using the Office of Faith-Based Initiatives to reward his political friends, using the Department of Justice to punish his political enemies, and using the fear of international terrorism to radically expand executive power.
7. Richard M. Nixon
The same can't be said for Nixon, who stonewalled further progress on civil rights, created the federal War on Drugs apparatus, and expanded the power of the presidency so much that his administration is still the "imperial presidency" by which all other unitary executive presidencies are judged.
6. John Adams
Frustrated by supporters of Thomas Jefferson in the press who criticized Adams, the thin-skinned president supported new federal sedition laws targeting anyone making unsubstantiated remarks about a government official. Adams had some of Jefferson's most prominent supporters arrested under the law, but it didn't do him much good--Jefferson won the presidency in 1800, and Adams' Federalist Party never won national office again.
5. James Buchanan
But when we think of Dred Scott v. Sandford (1857), we don't think of James Buchanan--and we should. Buchanan, who made pro-slavery policy a central tenet of his administration, boasted in advance of the ruling that the issue of slavery expansion was about to be resolved "speedily and finally" by his friend Chief Justice Roger Taney's decision, which defined African Americans as subhuman non-citizens.
4. Millard Fillmore
Fillmore's bigotry wasn't limited to African Americans. He was also noted for his prejudice against the growing number of Irish Catholic immigrants, which made him extremely popular in nativist circles.
3. Andrew Jackson
When Jackson discovered gold on Cherokee land in Georgia, he simply ignored existing treaties and had one of his own agents, John Ridge, "negotiate" the Treaty of New Echota on behalf of the Cherokees--forcing their displacement on what became known as the "Trail of Tears."
Jackson is also the only president in U.S. history to openly defy a Supreme Court ruling. In response to Worcester v. Georgia (1832), Jackson was reported to have said: "John Marshall has made his decision. Now let him enforce it!"
2. Woodrow Wilson
The lowlights of his administration include the Sedition Act of 1918 (which criminalized all radical criticism of the government), the Palmer Raids (in which he ordered the arrest and attempted illegal deportation of over 10,000 people), and numerous specific instances in which he ordered dissenters to be silenced. America under Woodrow Wilson was a nation under lockdown.
1. Andrew Johnson
-- Andrew Johnson, 1866
Johnson was the worst president in U.S. history. It's not because he created Jim Crow, although he did. It's not because he fought passage of the Fourteenth Amendment, although he did. And it's not because he failed to create a way forward for Southerners of all races, condemning the South to over a century of poverty--though he did that, too.
No, it's because he did all of this because he could. He wasn't a wartime president; he faced no new terrorist threats. He just inherited the presidency and used it to push his own prejudices. History has never forgiven him for that, nor should it.