News Analysis: Republican candidates need more star power to beat Hillary Clinton in 2016 U.S. presidential race

With several Republican Party (GOP) candidates for the 2016 U.S. presidential race ramping up their game and jockeying for the spotlight in recent weeks, one thing is clear: none appears particularly exceptional, at least not yet.

That was obvious at a GOP political convention in the U.S. state of New Hampshire over the weekend, which was a chance for candidates to get out in public and strut their stuff. The field is still wide open, with no obvious front-runner among the pack, and no dominant personality who is significantly ahead in the polls.

It will be important for candidates to build up their own star power if they are to rival likely Democratic nominee Hillary Clinton, who is one of the country's most recognizable political personalities.

Nevertheless, it's still early, with candidates just getting their feet wet, and candidates still have time to improve their game for the 2016 race to the White House.

Indeed, every race sees candidates rise to unexpected challenges and others, who seem to be on top early on, can sink in popularity.

That was once the case with Hillary Clinton's husband and former U.S. President Bill Clinton. During his keynote speech at the 1988 Democratic Convention, he was greeted by boos by an unfriendly crowd as he droned on with an unexciting, dull and unusually long speech.

But in the next four years, Bill Clinton upped his game dramatically, transforming himself into an exciting candidate for change even playing a rock-and-roll song on his saxophone on a late night talk show. He later won the presidency in 1992 and went on to become a very popular president.

"The challenge right now for the GOP candidates is that they're all vying on a more crowded stage for support from a more divided party," Dan Mahaffee, an analyst with the Center for the Study of the Presidency and Congress, told Xinhua.

"As the field solidifies and some of the less viable candidates drop out, you may see one of the presumptive front-runners - Jeb Bush, Scott Walker, Marco Rubio, or Rand Paul -- start to garner more excitement," Mahaffee said of a handful of Republican candidates viewed as having more potential and financial backers than others.

"Leaders can definitely step up to the plate and distinguish themselves, and that's why despite the early strength of (former Florida Governor) Jeb Bush as the establishment candidate, there's still plenty of attention being paid to the younger up-and-comers, " Mahaffee said.

Among Democratic circles, some believe Florida Senator Marco Rubio, at 43 years old, could be the most dangerous Republican rival for Clinton, as he could present a youthful narrative and position himself as a next-generation politician, he said.

But Jeb Bush is the best known of the potential 2016 GOP candidates, with 76 percent of Republicans and Republican-leaning independents familiar enough with Bush to have an opinion of him.

According to a recent Gallup poll, a major factor in potential 2016 candidates' weaker favorable ratings, compared to others in U. S. presidential campaign history, is that none is as well-known as the early front-runners in the past.

In past primaries, several candidates have enjoyed a familiarity rating of higher than four of every five Republicans. For example, former President George W. Bush, Jeb Bush's elder brother, was at 91 percent at a similar stage of the 2000 campaign, Gallup found in a recent poll. Endite