No you are supposed to nominate candidates that can actually win. If you think a candidate that could barely get 50% of her own parties votes is going to sweep to victory, you have been smoking something illegal.
So you'd be supportive of nominating John McCain for the Whitehouse. And here's a newsflash for you...it is entirely common for the winners of a general election to have recieved less than 50% of the vote in their primary race. How long have you been following politics Dave?