I'd be very surprised if he got the GOP nomination. Granted, the GOPers are trying to figure out how to make Trump go away without pissing him off enough to go third-party, and they seem scared of Cruz, too, with good reason. The "establishment" GOPers (what's left of them) are trying to figure out how to nominate somebody who isn't as obviously criminally insane as Jeffrey Dahmer. That leaves Jeb!, Kasich and Rubio. Rubio has the same problem as Jeb!: He seems limp, dull, and uninspiring - and doesn't even seem to be trying. Maybe they'll try to install Kasich, who actually is pretty horrible, too, but doesn't seem as mad as a box of frogs like most of the rest of them. In any event, notwithstanding some polls suggesting Rubio could beat Hillary, I doubt very much that they'll nominate him. They have to get rid of Trump, for starters.

best chance for victory. He's had pretty good press and the other republicans really haven't attacked him yet. He's very untested. I'll be interested in seeing how well he holds up under pressure. Personally, I think the guy is an empty suit that will wilt in the spotlight if he gets that far.

But as it turns out, the baggers were really starting to make waves and Hunstman didn't stand a chance. Same will go for Rubio. We Dems may think he's a threat, but the Reps seems to want to place a more frightening, extremist figure at their helm. Idiots.

will the voters think so? or realize this in time?

He is an empty suit, for sure. Listen to him some time (like for instance, in tonight's debate). He has this superficial "fluency" of speech, but IMHO it's all fake: words flow out, but when you stop to think, 99% of the time he hasn't really SAID anything. Also, his claim to foreign policy "credentials" and "experience" is laughable, at best.

But will the voters see this?

Then there is his naked ambition. So far in his career, he has let nothing or no one get in the way of his climb to the top: not his colleagues who once supported and mentored him, not his official responsibilities as an elected Florida or US Senate legislator; not "minor" issues like integrity or honesty. He really is a slime ball.
Like Palin: if he doesn't take his current job as US Senator seriously, how can he be expected to take the presidency seriously?

But again, will the voters see all this, or will they see only his relative youth and his "attractive wife"? I admit to low confidence in the American electorate.

And then we add in the Republican Slander Machine and attempts to suppress voting rights across the country.

The Dems and (if she's to be the nominee) Hillary's campaign staff have to be at the top of their game in this election.

That's how she does it. She won't be more concerned about any of them. She understands the stakes very well. She wouldn't go into the general stating that she is going to handcuff herself monetarily. Now that's irresponsible and shows that the threat of republicans isn't understood. Clinton and her supporters will take Rubio on with all we have.

When the younger voters ( who are the ones who picked him over Clinton) find out his views on marriage equality, abortion ( none, no matter what) and contraceptives, plus his other crappy views, they will not be swayed by his youth and good looks.

Most young voters aren't really following that stuff yet.

I'm not worried at all about Rubio.

He will get shellacked at debates.