Question for the polling junkies here -
I keep hearing that Trump "overperforms" relatives to the polls. I totally get in 2016 this would have applied, but question that now. I've also heard Dems are under-represented in polls, because younger Dem voters don't have landlines and tend to not engage with numbers they don't recognize
Which is true? Assuming the work is done by an honest pollster with no inherent bias, which candidate is actually under-represented?