Ron Paul announced today he will not devote any resources to earning votes where ballots haven't already been cast. He will apparently fully devote his campaigns resources to subverting the will of those voters who have already gone to the polls. As demonstrated in several states such as Maine, Massachusetts, Louisiana, Minnesota, Nevada, Iowa and others, Paul and his supporters are masters of manipulating the system to help their guy, and it makes sense that he would devote his resources to that end.
To be clear, they have done nothing illegal. If you are of the (correct) view that our political system is not a democracy, they haven't done anything unethical.
What they have done is a combination of tricks aimed at maximizing the number of Paul supporters at this summer's convention. They recognize that while the media follows the beauty contest vote, what really matters is the delegates. They might move to have a caucus do the beauty contest vote first and then elect delegates to the county caucus after, letting the less-informed voters go home thinking they've done their bit with their beauty contest vote. They have volunteered to serve as delegates for other candidates, knowing that, depending on their state, they are only obligated to vote for the other candidate on the first ballot, or are allowed to abstain in Round 1 and then vote Paul, or are even allowed to vote for Paul on the first ballot anyway. They have aggressively lobbied for the support of delegates pledged to Santorum, Gingrich and others.
All of these things are much cheaper and more effective than going on the air with millions of dollars worth of ads. While it is unlikely that these tactics will prevent Romney from winning the nomination, it will at least make for an interesting convention. Who's to say that Paul doesn't have dozens/hundreds of ersatz Romney delegates ready to swing the nomination to Paul if they can prevent Romney from getting to 1,144 votes on the first ballot.
So it's at least on the table that the man who won an overwhelming plurality of votes wouldn't win the nomination. Stay tuned.