What is it that Democratic primary voters want in a candidate?  Since shortly after the 2016 election, when pollsters first began to take the temperature of Democratic voters, former vice president Joe Biden was the clear choice among Democrats.

Biden is still the frontrunner, but some of the rest of the field has caught him.  A survey from Change Research, a left-leaning polling outlet, shows that Biden is the choice of 21% of Democrats, followed by Bernie Sanders at 20%.  Significantly, Biden has lost 15 points just since last month, and Sanders has lost 4 points.

Where did many of those voters go?  They've hopped on the Pete Buttigieg bandwagon.  The South Bend mayor has gained 15 points in the last month.

Is the poll an outlier?  Maybe.

The Hill:

Still, the Change Research poll finds Buttigieg polling much higher than other surveys.  He is at 9 percent in an Emerson College survey and 7 percent in a Morning Consult poll, both released this week. 

Buttigieg was relatively unknown nationally before a CNN town hall event last month caught the attention of Washington insiders and spurred growing buzz surrounding the 37-year-old Midwest mayor.

In the past few weeks, Buttigieg has become a media sensation and a serious contender, raising $7 million in the first quarter and landing several coveted donors who previously raised millions of dollars for the Obama-Biden ticket.

No other candidate is polling in double-digits in the Change Research survey beyond Biden, Sanders and Buttigieg.

Former Texas Rep. Beto O'Rourke is at 9 percent, followed by Sens. Elizabeth Warren (Mass.) and Kamala Harris (Calif.), at 8 percent and 7 percent, respectively.

Buttigieg's numbers may not be as robust as those suggested in the Change Research survey.  But I don't think there's any doubt his star is rising, and if he hasn't already surpassed O'Rourke, Warren, and Harris, he soon will.

Buttigieg is a genuine electoral phenomenon who has risen as a result of a clever media strategy.  In some ways, his efforts at getting free media are reminiscent of Donald Trump's campaign in the early going, appearing anywhere and everywhere the news nets would have him.  Trump made himself a serious candidate by simply outhustling the competition.  Buttigieg appears to be trying to do the same thing.

All of this is subject to change, of course.  The first Democratic debate is scheduled for June, and you can expect every candidate to try to make a splash to separate themselves from the massive clutch of candidates.  But Buttigieg is raising money hand over fist, and he isn't likely to fall very far, no matter what happens at the debates.