“Some Donald Trump Voters Warn of Revolution if Hillary Clinton Wins”
Ashley Parker and Nick Carasaniti, New York Times, 2016-10-27
Those threatening "revolution" if Donald Trump loses the Presidential Election don't really know the U.S. Constitution.
As to the elections being "rigged" consider
"Each House shall be the Judge of the Elections...of its own Members..."
- U.S. Constitution, Article I, Section 5
This means that the outgoing House and Senate get to judge the elections to keep themselves in office or to judge the fairness of the election of their replacements. If the Clinton "landslide" many are predicting comes true, wouldn't many members of Congress be out of office? Do you really think there are so many Republican members of Congress who believe the elections are "rigged" that they would nullify the election of their successors? Given the number of congressional Republicans disavowing Trump, I seriously doubt they would nullify the election of their replacements.
As to having a "revolution" consider
"The Congress shall have the power "To provide for calling forth the Militia to ... suppress Insurrections..."
U.S Constitution, Article I, Section 8
Whatever the result of the election, would not most members of Congress, Republican or Democrat, be repulsed by an insurrection in support of a defeated Presidential candidate?