It would be difficult for Mitt Romney to do anything now that 80% of Obama hating Americans would really care about.
That'd be a first step towards being helpful.
The two sides are always fairly evenly matched. This race is different though ~ both Romney and Obama have a large number of potential voters who do not support either one of them and would feel disgust about casting a vote for either one.
The only question is how many of them will act on moral principles and/or self-interest and NOT vote for either one.
It is possible we could get a Constitutional majority in the House and the Senate and watch Romney go down to defeat.
Obviously the Constitution would give us the prerogative of removing the President and putting our own guy in ~ just like a parliament selecting a new Prime Minister, so that wouldn't be a Constitutional catastrophe.
But MItt can end all that speculation now by dropping out and leaving it to Republicans to select their own candidates. We really don't need his kind.