When a majority vote does not yield a president

I believe that if no clear majority is reached by popular vote, that the 2 front-runners should have a second election between them.
In 2000, it was said that a vote for Nader was a vote for Bush. This was because the people voting for Nader would most likely otherwise have voted for Kerry, and so he was taking Kerry’s votes. Had I been old enough to vote in that election, I would have voted for Nader because I felt that he was the best choice for president. But if he were not there, my vote would have gone to Kerry. I don’t want to be unable to vote for my first choice for president, for fear of screwing things up for my second choice.
A second, run off, election would fix that problem entirely.