First Trump-Clinton debate has yet to convince undecided voters

"It satisfied his supporters in this regard and he never completely lost control of his temperament," the professor said.

Brandon Rottinghaus, a professor of political science at the University of Houston, agreed. "He kept his temperament in check for most of the debate but responded to a few taunts from Clinton."

"As the challenger, Trump's demeanor felt more appropriate than expected from the temperamental Trump we often see on Twitter. He animated but it more often came off as passion instead of contrarian," Rottinghaus told Xinhua.

UNDECIDED VOTERS

Monday night's presidential debate was the first of three matchups between Trump and Clinton, both of whom polls show are the least liked presidential candidates in modern history. The highly anticipated face-off was seen as a chance to help swing and independent voters to make up their minds with the Nov. 8 election day only six weeks away.

A Reuters/Ipsos poll released on Monday showed half of America's likely voters would rely on the debates to help them make their choice.

In the first, high-stakes debate hosted by Hofstra University in New York, "both candidates were more wonky than warm, and both failed to connect to the people in a direct way. Neither came off as a good politician," Rottinghaus said. "It felt like both were talking to their base to gin them up rather than talking to undecided voters."

Many voters felt the debate was more about entertainment than about policy positions, as Trump, a New York businessman and former reality TV star who has not been elected to public office, and Clinton, a former senator and secretary of state, sparred only superficially on the economy, racial relations and foreign policy issues.

Trump, who was expected to seize the opportunity to dispel lingering voter doubts about his knowledge and character, did not do a good job in demonstrating he is qualified for the White House, Shapiro said.

He did not help himself in this respect with voters on the fence because "he was at times argumentative and lost some coherence and did not look presidential," he said. "With the exception of trade and jobs, he showed no particular competence and capability to show any further qualifications to be president."

Although Clinton may have gotten the upper hand in convincing undecided voters that she is the better choice, she may not have helped herself in increasing support among those 18-30-year-old voters who are supporting Libertarian candidate Gary Johnson and the Green Party's Jill Stein and Trump -- and increasing turnout of this group, he said.

"The net effect over the next week may be that Clinton will pick up a percent or two in the polls -- but not a major effect other than stopping her recent loss of support," Shapiro said.