Marco Rubio might have been a phenom who rose too quickly - or was never going to make

Sen. Marco Rubio. Photo / AP

Looking back on the 2016 presidential field, there was no candidate who seemed to hold as much potential or engender as much excitement as Sen. Marco Rubio, R-Fla., did. His family's story was inspirational. He had a winning smile and could produce stirring rhetoric.

And yet there had been warning signs that the exterior charm and eloquence were not matched by internal fortitude and mature judgment. After a heroic effort on immigration reform, he not only went mute when the bill left the Senate, but he also plunged head-long into the inane shutdown effort. He did not lead the charge, but he mimicked the ridiculous arguments (e.g. the president would be the one shutting down the government, the public's anger over Obamacare would carry the day). It seemed a blatant effort to patch things up with the far right, which had become infuriated with his immigration effort.

Then there was the Syria "red line." If ever there was an issue that demanded Rubio's support, this was it. He, more than most, understood the enormity of the ongoing bloodbath, the risk that jihadists would take hold and the essential task of projecting U.S. power. Yet once again he blinked, siding with the far right, refusing to take the intellectually consistent and courageous position in support of a military strike.

Next came Rubio's opposition to an aid bill for Ukraine, opposed by the far right because it contained a reform of the dreaded International Monetary Fund.

And while his campaign began with much promise and high expectations, he again faltered at key moments. New Jersey Gov. Chris Christie ate his lunch at the debate before the New Hampshire primary. When given a chance to break with the pack, show real leadership and declare that he would not support the know-nothing, bigoted, misogynistic, deceitful Donald Trump, he again blinked. Despite all the criticisms, he said he would support the nominee.

Now, after his race is over, Rubio again refuses to stand up and stand tall against the cranks in his party. He proclaims that Trump's "performance has improved significantly." Really? I am curious to know whether Rubio thinks the Trump foreign policy address, littered with contradictions and absurdities, was a significant improvement. What about Trump's embrace of Mike Tyson and denial that he is a convicted rapist? His assertions that we should give the bomb to South Korea and Japan and pull back from NATO? Judging by his silence on these issues, Rubio seems no different from rank opportunists such as Newt Gingrich. Even worse, Rubio went so far as to support Trump's argument that he does not really need a majority. "I do think it's valid to argue to delegates: 'Look, let's not divide the party. You have someone here who has all these votes, very close to get 1,237, let's not ignore the will of the people or they're going to be angry.' " Yes, we wouldn't want to anger the mob that Trump has stirred up.

What does all of this say about Rubio? Frankly, it tends to confirm Jeb Bush's view of the man. Bush argued that Rubio was untested, short on internal strength and too eager to be liked. It was not a matter of experience -- although that was sorely lacking -- but of character. This was not Jeb Bush's year. But he had Rubio's number. What a waste. What a shame.