Quite honestly, Bush’s legacy his first four years and the Republican Party would have been far better off if Kerry had won the 2004 election.
Bush would still be a hero and not a party pariah.
Kerry would have got that real estate bubble that burst(and would have happened regardless who was president) and nobody would’ve e been able to blame Republicans for that mess.
We would have won the 2008 election and the country would be far better off today.
And Barack Obama would still be an obscure Senator from Illinois, a failed state.
Unfortunately, we can’t relive the past.
And if Gore had pulled off 2000 I think it highly likely the democrats would have seriously bungled the response to 9/11 (Holder style civil trials in downtown Manhattan, etc.) and we'd have probably gotten a solid GOP congressional majority and different president in 2004.