If every Anderson vote had gone to Carter, Reagan still would have won.
"Minus the sabotage of the Hostage" negotiations: That would have required exposure while it was happening, which wasn't particularly likely what with Bush being a former CIA director, and a lot of intelligence people ticked off at Carter and Ramsey Clarke.
And for lack of investigation you're blaming the ACLU? What about all the mainstream party Democrats, the forerunners of the current "centrists", who made sure investigations never dug too deep, and never went to the jugular. It wasn't the ACLU who said the following in 1986:
Sen. Daniel Patrick Moynihan (D-N.Y.), noting that he served in the Cabinet of Republican President Richard M. Nixon, urged President Reagan on Saturday to "clean house," saying, "This nation does not need and does not want another failed presidency."
Portraying the crisis over secret arms deals with Iran and clandestine payments to Nicaraguan rebels as transcending partisan politics, Moynihan told Reagan that "your presidency, sir, is tottering." And he added, "We want you to save your presidency, our presidency."
I recall that John Kerry's investigations of Reagan were continually marginalized by the Democratic leadership.
I recall that once Bill Clinton came into office -- meaning that the targets of the investigations were no longer in a position to obstruct those investigations -- his people were specifically asked about getting to the bottom of a multitude of Reagan/Bush scandals, and the word was that "that's just not on their radar screen". "Look forward, not back" Version 1.0. You remember how the appreciative Republicans thanked him, right?
But hey, rather than hold the party leadership to account for their lack of action and even cooperation, why not grind some axes, eh?