The dept of homeland security decided to not allow new yet legal immigrants to vote this year.

Troops who vote by absentee ballot have their votes disallowed since their address is technically overseas but are instructed to put their home military training base as their residence. Since they are not at that base any longer their usually democratic votes are not counted.

A young former judge Rhenquist used to send home black voters from the polling place when they could not present proof of citizenship to his satisfaction.

This is an old tactic that is being refined more today than people realize.