To determine whether the votes in Mississippi and New Jersey reflect the overall results of a specific presidential race, you would need to check the election results for that year. Generally, Mississippi tends to lean Republican in presidential elections, while New Jersey typically leans Democratic.
If you're referring to a particular recent presidential election, for example, in 2020, Joe Biden won the overall election, and he also won New Jersey. Meanwhile, Donald Trump won Mississippi. Thus, in that election, Mississippi did not reflect the overall results of the presidential race, while New Jersey did.
For the most accurate answer, it would be best to specify which presidential election year you are interested in.