Look back at the main page at Race to 270
Switch the electoral votes in your states with the outcome of the 2020 Election (give those votes to the loser and recalculate. If new jersey or Mississippi had gone the “other way” would the outcome of the 2020 election change? If so, which state and why? If not, why not?
If we switch the electoral votes in New Jersey and Mississippi with the outcomes of the 2020 election (giving those votes to the loser), the outcome of the election would not change.
New Jersey had 14 electoral votes in the 2020 election and went to Joe Biden. If we were to give those votes to Donald Trump (the loser in New Jersey), it would not be enough to change the overall outcome as Biden won by a large margin.
Similarly, Mississippi had 6 electoral votes in the 2020 election and went to Trump. If we were to give those votes to Biden (the loser in Mississippi), it also would not be enough to change the overall outcome as Trump won by a significant margin in that state.
Therefore, the outcome of the 2020 election would not change even if New Jersey or Mississippi had gone the "other way."