This probably can't be solved at the voter level either. The old Concertación base cares first and foremost about keeping the right out of power, and they have never forgiven the Broad Front for letting Piñera in. Take for example, my mom. She has voted in the first round for a left-wing alternative candidate in every presidential election since 1990. On the issues she agrees with them more than with Progressive Convergence. But she would never vote for them because in her eyes they only are the right useful idiots. Hell, my whole extended family spents all day complaining about how sh**tty the center-left parties are but they would never even consider voting for the Broad Front after what happened in 2017. But as I said, Progressive Convergence doesn't have any political project or vision, so they are also unlikely to benefit from the government chaos or recuperate its former voters.
In what sense is the Broad Front blamed for getting Pinera elected? Did they fail to endorse the centre-left candidate for the second round in the Presidential election?