Describe a Norman Thomas 1948 voter

[Blow by blow, the passion dies]

Maybe someone in Milwaukee who liked the sewer socialist administration, or just a democratic socialist, SPA or not.

[patzer]

...someone who believed Norman Thomas was the best person to vote for as President?

I'm not sure if I'm missing something here. The demographics of Norman Thomas voters across the US by state are known, as the results of the election are available on wikipedia. Regarding your example of Milwaukee, Norman Thomas received 0.98% of the vote in Wisconsin- 12,547 votes, the second most of any state after New York.

[Snowstalker Mk. II]

Thomas explicitly catered to the anti-Stalinist left, which is probably just your answer.

[Dr. Cynic]

A leftist that didn't like how chummy Henry Wallace was with the Soviet Union.