Question

What was the important precedent set by the Gitlow v. New York case?

The equal protection clause was dropped from the Fourteenth Amendment.
The due process clause was dropped from the Fourteenth Amendment.
First Amendment freedoms were incorporated into the Fourteenth Amendment.
Fourteenth Amendment rights were incorporated into the Fifteenth Amendment.

Answer 1

First Amendment freedoms were incorporated into the Fourteenth Amendment.

Gitlow (1925) established that the First Amendment's free speech protections apply to the states through the Due Process Clause of the Fourteenth Amendment (the doctrine of incorporation).