Brendan McCarthy just posted Meryl Streep leading a standing ovation for disgraced, should be in prison director Roman Polanski back in 2003. I think that says it all.
But I think 2016 was the year the public decided that celebrities would not sway them and often would actually make them go the other way. Brexit was very much going Remain until Eddie Izzard appeared on Question Time in a disastrous performance that I think was the turning point, the audience actually booing him (which I’d never seen before). The Scots Referendum in 2014, the 2015 General Election, Brexit and the Presidential Election all went the opposite way from the celebrity consensus aimed at the electorate.
I would say now that celebrity endorsement is a liability. Voters want someone who look like them up there.