Refusing service because of political party.

[Joods]

Double jeopardy would come into play here. The case was tried and went to the jury where a decision was rendered. Once that happens,  you then need to go through the appeals process,  which is evidently how the case got overturned.

Double jeopardy laws prevent the same person from having the same case tried against them twice, once a verdict has been returned.

I could be wrong but I believe that on appeal the previous verdict is thrown out, no new verdict is given (can't change guilty to innocent, just remove guilty). The prosecution then has to decide if they are going to retry the case or not. 

https://www.americanbar.org/groups/publi...peals.html

https://en.wikipedia.org/wiki/Double_jeopardy   (take note of valid acquittal or conviction)

I think I watch more Law and Order than you.

Google 5th amendment. It says the following:

No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger; nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.

I will say that not every case goes through the appeals process. But a person cannot get tried for the same crime twice as it would violate their 5th amendment rights.