Bill Clinton wasn’t untouchable when he was impeached. He just wasn’t convicted, mainly because what he did wasn’t worthy of the clause “high crimes and misdemeanors.â€
He's not untouchable now...except for the fact that nobody wants to touch him.
https://qz.com/1182889/bill-clintons-declining-legacy-monica-lewinsky-impeachment-metoo-and-trump/
But lately, Clinton’s scent seems to be turning fetid. For the first time since he left office in 2001, more Americans view Clinton unfavorably than do favorably. After peaking at 69% in 2013, Clinton’s favorability rating has slumped to 45%. This trend is unusual among retired presidents. Most can count on nostalgia to sanctify even the most benighted tenure; even the once heinously unpopular George W. Bush enjoyed favorability ratings of 59% as of late 2016.
Of course that's not due to impeachment but rather the "me too" movement, still it's nice to see the guy who needed everyone to like him get his reward for being a sexual predator.