McGovern was viewed as a left wing extremist (term not used those days)and would have had a hard time attracting anyone that was not much left of center in the political spectrum.

Carter had an economy that was impacting everyone with out of sight interest rates, inflation going ballistic and confidence in the American way of life at its lowest level in years.

George H was running a campaign where the center right voter was splitting their votes between Bush and Perot. What would have been with a two way race?

Clinton most likely would have defeated Dole as Dole had high negatives before he was nominated due to his “attack dog” past for prior candidates. And with an economy going great and balanced budgets, what would have caused his defeat?

As for Obama, discuss his lack of leadership in domestic affairs where he does not give any material direction to congress and lets Pelosi and Reid drive the train his first two years. Other than dividing the country between 99-1, which is nothing but a campaign strategy, where has his leadership been in key decisions?