From immigration to income inequality, it's clear why the Republican and Democratic primary elections are playing out in such starkly different ways: Both parties are talking to electorates that look very little like each other - or like the general election voters who won't go to the polls until next November.
A new super-sample of the last three NBC News/ Wall Street Journal polls - composed of a combined 999 GOP primary voters and 1,030 Democratic primary voters - shows how dramatically different the two pools look demographically and ideologically.
A whopping 92 percent of those GOP primary voters are white, compared to just 72 percent of the general electorate back in 2012.
Just one percent are African American (compared to 13 percent of the electorate overall) and four percent are Hispanic (compared to 10 percent overall.)
GOP primary voters also skew male, with men comprising 54 percent of the Republican electorate and 47 percent of the general electorate.
Democratic primary voters, on the other hand, are less white than general election voters overall. Sixty-two percent of Democrats planning to vote in the nomination contests are white, while 38 percent are non-white.
And the Democratic electorate is more female (58 percent compared to 53 percent) and more highly educated than voters at large, too.
It's no surprise that primary voters on both sides are more ideologically extreme than those who only cast a ballot in November, but the breakdown is fairly stark.
Among Republican primary voters, 69 percent describe themselves as conservative, 25 percent as moderate, and five percent as liberal.
Among Democratic primary voters, it's nine percent conservative, 39 percent moderate and 50 percent liberal.
According to 2012 exit polls, the general electorate looks more like this: 35 percent conservative, 41 percent moderate, and 25 percent liberal.