The Fourteenth Amendment accomplished many different things at once. It granted citizenship to all people born in the United States - most importantly, people formerly enslaved. It guarantees that all people in the U.S. enjoy the same privileges and immunities and that the government may not infringe upon those rights without due process of law.
A seldom discussed section of the Fourteenth Amendment is the apportionment clause, which aimed to punish southern states that refused to grant African Americans the right to vote after the Civil War.
"Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State, excluding Indians not taxed. But when the right to vote at any election for the choice of electors for President and Vice-President of the United States, Representatives in Congress, the Executive and Judicial officers of a State, or the members of the Legislature thereof, is denied to any of the male inhabitants of such State, being twenty-one years of age, and citizens of the United States, or in any way abridged, except for participation in rebellion, or other crime, the basis of representation therein shall be reduced in the proportion which the number of such male citizens shall bear to the whole number of male citizens twenty-one years of age in such State."
United States Library of Congress, The Constitution of the United States of America: Analysis and Interpretation
With the abolition of slavery by the Thirteenth Amendment, enslaved persons and their descendants (formerly counted as three-fifths of a person) would be fully counted in the apportionment of seats in the House of Representatives. This increased the electoral vote, and the prospect appeared that the readmitted Southern states would gain a political advantage in Congress when combined with Democrats from the north.
Because the South was adamantly opposed to African American suffrage, all the congressmen would be elected by white voters. Many wished to provide African Americans the right to vote, and proposals to this effect were voted on in both the House and the Senate. But only a few northern states permitted African Americans to vote, and a series of referenda on the question in the northern states revealed substantial white hostility to the proposal. Therefore, a compromise was worked out to give southern states an incentive to grant African American males the right to vote - because if they didn't, they would lose representation in Congress.1
No serious effort was ever made in Congress to enforce § 2, and the only judicial attempt was rebuffed.2 Subsequent constitutional amendments and other federal mechanisms granted the right to vote, making this section little more than a historical curiosity.3
However, in Richardson v. Ramirez,4 the Court relied upon the implied approval of disqualification upon conviction of crime to uphold a state law disqualifying convicted felons for the franchise even after the service of their terms. It declined to assess the state interests involved and evaluate the necessity of the rule, holding rather that because of § 2 the Equal Protection Clause was simply inapplicable.