Bernie Sanders’s campaign has had far more success than most people (including this guy) thought it would. He has gone from a virtually unknown Vermont senator to winning a little more than 40 percent of the national Democratic primary vote. He will probably fall short of the nomination in the end, but why has Sanders outperformed expectations so much? Here’s part of an explanation: The Democratic electorate turning out in 2016 has been a lot more liberal than it was in the last competitive Democratic primary, in 2008.

“VERY LIBERAL” SHARE OF VOTERS STATE 2008 2016 DIFFERENCE Alabama 16% 27% +11 Arkansas 12 22 +10 Florida 21 20 -1 Georgia 18 23 +5 Illinois 20 29 +9 Iowa 18 28 +10 Massachusetts 22 29 +7 Michigan 19 22 +3 Mississippi 15 27 +12 Missouri 14 28 +14 Nevada 18 33 +15 New Hampshire 20 26 +6 New York 22 29 +7 North Carolina 16 26 +10 Ohio 13 23 +10 Oklahoma 10 18 +8 South Carolina 20 23 +3 Tennessee 16 25 +9 Texas 15 20 +5 Vermont 26 33 +7 Virginia 17 29 +12 Wisconsin 16 25 +9 Total 17 25 +8 More “very liberal” voters in Democratic primary exit polls Source: Edison Research

Interestingly, the Democratic electorate has shimmied to the left roughly equally in the South and outside the South. The very liberal percentage of the Mississippi vote, for example, was up 12 percentage points, while it was up 15 points in Nevada. Voters outside the South were only slightly more likely to identify as very liberal (nearly 27 percent) than voters overall. So why did Sanders still do so poorly in the South? Black voters accounted for a much larger percentage of the very liberal vote in Southern states.

Sanders, though, was definitely helped by voters’ being in a more liberal state of mind. The very liberal voting bloc was Sanders’s best — or tied for his best — group in every contest so far. On Tuesday, for example, Sanders won the very liberal vote in New York by 12 percentage points, even as he lost somewhat liberals by 18 points and moderates/conservatives by 32 points. Clinton’s margin of victory in New York would have been 3 percentage points bigger if nothing else changed except the ideological makeup of electorate looked like it did in 2008.

Moderate and conservative voters, meanwhile, are a much smaller part of the Democratic primary vote than they were eight years ago. In 2008, they made up 54 percent of primary voters in the states that have voted so far this year. That’s down 15 percentage points and generally matches the decline of self-identified moderate and conservative Democrats we’ve seen in national surveys.

It wouldn’t be surprising to see the moderate/conservative portion of the Democratic primary electorate become a minority in the next 10 years. It’s the youngest Democrats who are more likely to identify as “very liberal.” It could very well be that someone matching Sanders’s ideological outlook will be more successful down the road. At the same time, though, it’s also nonwhite Democrats (who are growing as a portion of Democratic voters) who are the most likely to identify as less liberal. Whoever the liberal alternative candidate is in the future will have to do better among nonwhite and especially black voters than Sanders did.

The fact that Sanders will likely lose the nomination, however, isn’t simply about race; the Democratic electorate is more liberal, but it’s still not all that liberal in an absolute sense. Moderate and conservative Democrats still form a larger base in most states than very liberal voters.

SHARE OF VOTERS WHO IDENTIFY AS “MODERATE” OR “CONSERVATIVE” STATE 2008 2016 DIFFERENCE Alabama 62% 43% -19 Arkansas 64 50 -14 Florida 49 46 -3 Georgia 53 44 -9 Illinois 52 36 -16 Iowa 46 32 -14 Massachusetts 41 30 -11 Michigan 51 43 -8 Mississippi 64 49 -15 Missouri 58 34 -24 Nevada 55 30 -25 New Hampshire 44 32 -12 New York 43 34 -9 North Carolina 58 44 -14 Ohio 59 41 -18 Oklahoma 63 55 -8 South Carolina 56 46 -10 Tennessee 59 39 -20 Texas 62 41 -21 Vermont 37 26 -11 Virginia 50 32 -18 Wisconsin 54 33 -21 Total 54 39 -15 Fewer “moderate” and “conservative” voters in Democratic primary exit polls Source: Edison Research

A little less than 40 percent of Democratic primary voters so far this year have identified as moderate or conservative. That’s 14 percentage points bigger than the very liberal bloc, and 4 points higher than the somewhat liberal group.

For all the hoopla surrounding liberal voters and the attention paid to them, they aren’t the base of the Democratic Party.

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Simply put, it’s difficult to compete in a Democratic primary if you’re consistently losing among moderate and conservative Democratic voters. According to the exit polls, Sanders would have won Iowa, Illinois, Missouri and Nevada if the contest had been held only among very and somewhat liberal voters. And while delegates are ultimately what matter, the trajectory of this campaign may have looked very differently had Sanders won Iowa and Nevada. Clinton would have lost the first three states of the primary season, and Sanders’s winning Nevada, a contest with a lot of nonwhite voters, would have sent the press into a tizzy. Instead, Clinton notched her only two stateside caucus victories of the race and her campaign took off.