Beto is following the same trend of apologizing for things: a reporter had him giving a 'sorry' for calling Ted Cruz "lyin' Ted" during the 2018 Texas senate debates.
Anyways, all the democrats need to do is go populist-left this election and also be unabashed in doing so. If they do that, they can add a counterweight to Trump's arrogant nationalism and right-populism.
Also to harp on the Sanders thing: the news said there was no evidence that he was even aware of the sexual harassment in his campaign, and he made clear that he didn't tolerate it. From that came claims by the gutter snipes in media that he paid women less. In reality, payments to volunteers and members of his campaign were not determined by any specific system, but by one-on-one negotiations for each individual. In a system like that of course there'd be disparities in salary.
We got Biden apologizing for putting blacks in jail in the past
Warren apologizing for pretending to be native american in the past
Gabbard apologizing for hating homosexuals in the past
Sanders apologizing for sexual harassement in his 2016 campaign
Tack onto all of this that:
Cory Booker apologized for supporting medicare for all
Kamala Harris backpeddled on medicare for all after one very minor question of pushback
Elizabeth Warren has rescinded her support of medicare for all