The two political parties seem to both want to become more extreme in their views. Many Democrats want their party to move further to the left, and many Republicans want their party to move further to the right. Both seem to think that is the way to appeal to the American voter. They both could easily be wrong.
If these polls are correct (and there's no reason to believe they're not), then a plurality of voters already see both political parties as too extreme. In the Morning Consult Poll, about 43% see the Democratic Party as being too liberal. And an equal 43% see the Republican Party as being too conservative.
The results of the new YouGov Poll is similar -- with 37% viewing the Democrats as too liberal and 36% viewing the Republicans as too conservative.
This leaves many voters in a quandary -- which party do they vote for, since they see them both as being too extreme? We know that most Democrats will vote for their own party, and most Republicans will vote for their own party. But neither has enough members to carry the 2018 election. That election, like most elections in this country, will be determined by Independents (most of whom are moderates).
I know my progressive brothers and sisters will not like this, but those Independents will mostly go for the party they see as the more moderate party. If the Democrats want to win in 2018, just being against Trump is not going to be enough. They must be viewed as the moderate alternative to extremist Republicans. And winning is the only thing that matters.
The Politico / Morning Consult Poll was done between September 14th and 17th of a random national sample of 1,994 registered voters, with a 2 point margin of error.
The Economist / YouGov Poll was done between September 17th and 19th of a random national sample of 1,500 adults (including 1,292 registered voters), with a 3 point margin of error.