“He poses the biggest threat by far,” said Susan Del Percio, the Republican strategist, who contends that Warren and Sanders are too far to the left to defeat Trump in the general. “They’re very left and the country is very middle.”…

“I speak to a lot of Democrats and a lot of people who I respect, say Biden is the best bet,” she said. “They feel like he’s the one who is unscripted and can take Trump on head on.”

Shermichael Singleton, another Republican strategist who served as a top aide to now-Interior Secretary Ben Carson during his 2016 presidential run, said he can’t see anyone beating Trump except for Biden “because of his ability to connect with blue-collar and middle-class voters.”