If I were invited to dinner and the vegetables were Brussel sprouts and turnips, I would not eat the vegetables, because I do not like Brussel sprouts and turnips. I would not tell the host that I wanted mashed potatoes and green beans, because that is not what was on the menu. It would be rude.
However, the political process is different. Citizens are supposed to be allowed a voice in what is on the menu. Preliminary news is that they are planning to serve up candidates that I don't like. First step in getting someone I do like is to let them know that the planned menu is going to be a flop.
There is plenty of time to plan for a successful event.
Your metaphor only works for dinner parties. And then only for small ones.
Campaigning to be Leader of the Free World requires enormous organizational and financial planning, and as such, it asks people to assume risk. People are asked to commit.
The only other conservatives that will get in at this point with the organizational or fund raising capability, even this far out, have to be either Governors or Gingrich, and may be General Franks. Rice or Powell, not interested.
Its amazing that Senators even bother. People can't stand them, and they don't have the executive experience that people are looking for in a President. Senators are much more followers than they are leaders. Leaders run for executive offices, retired lawyers run for representative office.