In 1865, the 13th Amendment was ratified; it abolished slavery. In 1868, the 14th Amendment was ratified; it granted citizenship to former slaves and their offspring born in the United States. Since amendments to the Constitution don't require the approval of the President, the Republican controlled Congress was able to ratify them without the consent of (Democratic President) Johnson. In between the ratification of those two amendments was the formation of a hateful and racist group known as the KKK in 1866. It was agroup formed by Democrats who felt threatened by the freedoms blacks were realizing as a direct result of Republican efforts.
The 15th Amendment, which gave blacks the right to vote, was introduced in 1869 and overwhelmingly supported by a Republican controlled Congress while being almost universally opposed by the Democrats in both houses. Not one Democrat in the House voted in favor of the Amendment, which was ratified in 1870. (Unsung Davids, p. 161)The KKK was formed by Democrats so that blacks could be intimidated and persecuted. After the 15th Amendment was passed, blacks were threatened with torture and death if they voted for Republicans.
Keep that in mind as you watch Bill Maher joke that blacks are ready to behave on November 6th as the KKK did in the 1870's. The entire black community should be outraged that Maher would make such a comparison.