Little-known Reconstruction-era laws may convict Trump for insurrection.
Special counsel cites three federal statutes in target letter to Trump.
Civil rights statute involves "deprivation of rights" or conspiracy charges.
The right secured by Constitution or laws would be the right to vote.
Trump sought to invalidate votes by pressuring Georgia officials.
Statutes used during the Reconstruction era to enforce Fourteenth Amendment.
Disenfranchising Black voters played a role in Trump's plan for victory