Which would be a more believable poll: a poll of likely voters; or a poll of voters in the 2016 Presidential election? I feel that if the person did not vote in the 2016 election, their opinion shouldn't count because they don't care. Furthermore, in 2019-20, polls should be based the opinions of those who vote in the 2018 Congressional elections.. Small adjustments could be made for younger voters who come of age in the interim.