Here are the two groups of voters who may determine 2020

Not surprisingly, much attention has been paid this cycle to these "double haters" (i.e. those who hold an unfavorable view of both Joe Biden and Trump). Less spoken about are those who hold an unfavorable view of neither Biden nor Trump, the "non-haters".

The double haters and the non-haters currently are a similar proportion of the electorate, but they differ wildly on who they support.

Our latest CNN/SSRS poll finds that the double haters go for Biden over Trump by about a 50-point margin. Our March poll had Biden ahead by around 60 points with this group. Given the small sample size, these results are well within the margin of error of each other. These polls are consistent with others showing Biden doing well with this group.

The non-haters are, on the other hand, going for Trump by a wide margin. They favor Trump over Biden in the horse race by about 45 points in CNN's May poll. Back in March, Trump was up by around 40 points -- again, a result that's within the margin of error of the May result.

In other words, Trump's pulling about as big of a margin out of the non-haters as Biden's pulling out the double haters in our data.

When you look at who is making up each group, the results make a lot of sense. Across our last two polls, double haters were more than 50 points more likely to lean Democratic in their party identification. In the 2016 exit poll, double haters were 15 points more Republican-leaning. This year, the non-haters have been about 30 points more likely to say they leaned Republican.

This year's data makes a lot of sense if voters are treating this election as a referendum on Trump. Those who dislike Trump (even if they also dislike Biden) are going with Biden overwhelmingly. Meanwhile, those who are seemingly OK with Trump are voting for him, even if they don't dislike Biden.

This also suggests that a strategy by Trump to drive up Biden's negative ratings may not work that well without a corresponding rise in Trump's ratings. In a referendum election, Trump is better off with both Biden and his ratings going up than he is by having both of their ratings go down.

For now, the two groups are of roughly even size. In our most recent poll, the non-haters are 10% of the electorate. The double haters are 13% of the electorate, which puts them within the margin of error of each other. Our last poll had them both at 13%.

That's very different than it was at the end of the 2016 election. The double haters were 18% of the electorate in the exit poll and 16% in CNN's final poll among registered voters. The non-haters are up from the 4% they were in the exit poll and 2% in CNN's final poll among registered voters.

This means that, at least for now, understanding how both groups are breaking down is necessary to fully comprehend what's going on in the electorate. Looking at just the double haters may overestimate Biden's chances.