News Analysis: Trump still tops Republican candidates, but Rubio clear winner at 3rd debate

While U.S. bombastic billionaire Donald Trump still leads the pack of Republican candidates, experts said Florida Senator Marco Rubio distinguished himself in Wednesday night's debate.

Wednesday evening saw the third Republican Party (GOP) debate in the race for the party nomination to face off against the Democratic candidate in the 2016 race to the White House.

While Trump continues to lead the crowded field of candidates according to Real Clear Politics' polling average, experts said Rubio dominated the nationally televised debate.

"Rubio was the clear winner of the debate," Brookings Institution's senior fellow Darrell West told Xinhua.

"(Rubio) came across as poised and calm in a chaotic debate setting. He played well to the conservative base and positioned himself as a leader who could bridge the GOP establishment and grass roots activists," West said.

Julian Zelizer, professor of history and public affairs at Princeton University, echoed some of those sentiments.

"Rubio has clearly emerged as the new possible frontrunner if Bush falls further," he said of former Florida Governor Jeb Bush.

Still, the populist Trump shows no sign of fizzling out, as so many analysts, experts, pundits and political prognosticators expected him to do early in his candidacy.

"Clearly some of the early fervor has died down and there is more space now for others ... to gain traction. But he is still a significant force based on the polls," Zelizer said of Trump.

A CBS/New York Times poll released Tuesday saw candidate Ben Carson speeding ahead of Trump with the support of 26 percent of GOP primary voters, against 22 percent for Trump.

While the poll is one of several and the Real Clear Politics average of polls still has Trump in the lead by 4.8 percent, it does indicate that Trump's momentum may be running out, and that his nomination is far from guaranteed.

While many of Carson's policies are similar to those of Trump, Carson is a much nicer version of the in-your-face and often insulting Trump.

Still, many experts do not see Carson, a retired neurosurgeon, getting his party's nomination.

"Carson leads the national polls, but it is hard to see him getting the nomination. His flat tax would bankrupt the federal treasury and he has not displayed the substantive depth one needs in a top leader," West said.

"He is doing well among those seeking a real outsider but it is not clear that his lead will hold up to the coming scrutiny of his record," he added.

Meanwhile, Bush, initially expected to be a shoo-in for the nomination and to face no significant opposition, is flagging in a struggle to gain media attention and stay relevant.

Despite being the son and brother of two former presidents, critics say he is boring and lacks an air of excitement around him. While he often discusses policies, American voters tend to gravitate more toward a candidate who appears to understand the struggles of ordinary Americans.

Moreover, his fundraising has slowed down considerably, and experts said the air of inevitability that he had six months ago is completely gone.

"Bush did not do well (in the debate). He was out-maneuvered by Rubio and seemed ill at ease among the attacks and counter-attacks," West said.

"He is not very adept at distinguishing himself on a crowded stage and he just does not present himself very effectively. There is growing unease among his donors that he is not up to this campaign," West said.

Zelizer said Bush is in danger of being forgotten.

"The troubles he faces have moved from a problem to being pretty serious, especially with Rubio right around the corner," he said. Endit