Democratic Party presidential candidate Joe Biden again took the measure of president Donald Trump, winning their second debate Thursday evening, and protecting his huge polling lead over Trump.

Various polls show Biden handily winning the raucous first debate against a bellicose Trump on Sept. 29.

A post-second debate CNN Instant Poll among 585 registered voters conducted by SSRS by telephone and interviews revealed 53% of those polled saying Biden won the face-off while 39% gave Trump the nod.

Trump did better this time around, however. His being chosen the winner by 39% of respondents compares to the 28% that said Trump won the first debate.

The second post-debate poll also showed viewers once again saying Biden's criticisms of Trump were largely fair. Seventy-three percent of respondents said so compared to the 26% that said otherwise.

On the other hand, 50% said Trump's attacks against Biden were unfair with 49% holding the opposite opinion. The CNN Instant Poll after the chaotic first presidential debate marred by incessant interruptions from Trump showed 67% of viewers calling Trump's criticism of Biden unfair.

A CNBC/Change Research poll conducted after the first debate found 53% of likely voters nationwide declaring Biden won the debate compared to 29% for Trump.

Only 2% of respondents said the debate changed their vote as against 98% who said it didn't. The same outcome is likely for the second debate with national polls showing only 5% of voters not having decided on their candidate.

Political pundits said Biden only had to remain calm and collected to win the second debate and protect his lead over Trump in national polls. The latest RealClearPolitics poll of polls average shows Biden with a 7.9% edge over Trump in the popular vote. The RealClearPolitics general election polling average after the first debate showed Biden with a 6.6% lead over Trump.

Biden has 232 Electoral College votes compared to Trump's 125. A total of 270 Electoral College votes are needed to win the U.S. presidency. Biden has a 66% chance of winning on November 3 based on betting odds, said RealClearPolitics.     

Trump, on the other hand, was faced with the impossible task of winning over undecided voters plus those that fled him in swing states for the second debate to reverse the fortunes of his flagging campaign.

Biden heavily attacked Trump's weakest point - his non-response to the COVID-19 pandemic - during the second debate. He said the U.S. is hurtling toward a "dark winter" due to the pandemic.

"We're about to go into a dark winter," said Biden. "And [Trump] has no clear plan and there's no prospect that there's going to be a vaccine available for a majority of the people until the middle of next year."

As expected, Trump resurrected the patently false claims Biden makes money from Russia, China and Ukraine.

"Joe got $3.5 million from Russia that came through [Russian leader Vladimir] Putin because he was friendly with the mayor of Moscow," Trump said. "I never got any money from Russia."

Biden shot back: "I have not taken a penny from any foreign source in my life. We learned this president does business in China, has a secret bank account in China and is talking about me taking money? I have not taken a penny from a single country whatsoever."

"No. 2...I released all my tax returns - 22 years, go look at them. You have not released a single solitary year of your tax return," Biden said. "What are you hiding? Why are you unwilling?"