Right now votes for a candidate who doesn't get a majority are thrown out, along with any preference for other candidates. When in life do we discount a 2nd best and go right to the worst? We don't, but our voting system is so simple it won't recognize when our 2nd choice is almost as good to us as our 1st. Similar values and plans for the U.S. are often shared among many candidates who should get our vote if our primary choice doesn't. We are voting for our values, not just an expressor of them!
We must be given the option to:
1.) Allow an alternative choice to inherit our vote should our primary choice not win.
2.) Constrain that inherited vote to our own political parties and candidates, one or more.
3.) Indicate our primary choice for the case of an instant majority.