'Clinton-izing Biden isn't working': GOP pollster warns Trump's attacks on Dem nominee are falling flat

President Donald Trump has tried to use the same playbook against presumptive Democratic presidential nominee Joe Biden that he used against Hillary Clinton in 2016 -- but so far it hasn't been working.

NBC News' Mark Murray on Monday posted polling analysis comparing negative feelings toward Clinton in 2016 with current negative feelings toward Biden.

At this point in the 2016 campaign, a total of 55 percent of respondents said they had negative views of Clinton, including 43 percent who had "very negative" views.

In contrast, just 38 percent of respondents in the latest NBC News/Wall Street Journal poll reported having negative views of Biden, and only 26 percent said they had "very negative views."

"So not only is Biden leading the ballot by a wider margin than Clinton was at this point in 2016, and not only is he besting Trump among voters who have an unfavorable view of *both* candidates," Murray commented. "He’s also much less unpopular than Clinton was four years ago."

Republican pollster Patrick Ruffini warned that the Trump campaign's belief that it can drive Biden's negative numbers down into Clinton territory may prove to be completely wrong.

"'Clinton-izing' Biden isn’t working, or at any rate, it hasn’t been tried," Ruffini wrote. "Clinton really was bad, sui generis, and not because Trump told people she was bad."