She is correct. Getting rid of an incumbant is difficult. Remember Ford, In a two man race in 1976, with all of the problems, got 48.0% of the vote.
I also read an article this morning which stated that many political historians believe that if it were not for the hostage crisis, which a very liberal Walter Cronkite mentioned EVERY SINGLE NIGHT as he signed off the nightly news, Carter would have won a second term. Even the last polls taken in late Oct of 1980 showed him several points ahead of Reagan.
Slick Willie was re-elected shortly after the BJ incident.
So yes, there is truth in that statement.