That other link was for the Dow. Here is a link for the S&P 500.
https://www.macrotrends.net/2482/sp500-performance-by-president
The Democrat Dow returned 4.5 times as much as Republican Dow. (jfk through obama)
The Democrat S&P500 returned 9 times as much as Republican S&P 500. (jfk through obama).
I hate to burst your ideological bubble but those are the facts. I am still waiting for your source that shows Republicans coming out ahead. I showed my data, your turn!