If Biden ends up being he candidate all we will hear from Trump is “Ukraine and Hunter a corrupt” or, “I had to roll back what they did, you can’t trust him”
I don’t see him as being a viable candidate to win, but then Sanders is too extreme for the US. I heard one interviewee on an exit poll say they had to choose Biden over Sandwrs because his Medicare-for-all would be too divisive.
Biden - particularly if he were to get financial backing from Bloomberg whose campaign is all but over - is a very strong contender. The Ukraine shit won't wash as it brings up too much dirty laundry regarding Trump's shenanigans.
For all the talk of Hillary Clinton's failed 'centrist' campaign, Biden isn't Clinton. Whether it's down to entrenched American misogyny or just plain personality, Clinton was a vegemite candidate and she was also a lazy one who took key states like Pennsylvania and Michigan for granted and did not bother to campaign in them and despite her faults, she still had 3 million more people vote for her than Trump.
Sanders is an even more divisive candidate than Clinton and one who's most fervent and loudest supporters happen to be from a narrow demographic with the poorest voter turnout. Biden's supporters cover a far wider range of age-groups and are more reliable when it comes to the polls. True, Sanders might be able to pull a few blue-collar voters away from Trump but I dare say it'd be at the expense of a significant portion of the middle class vote.
