The poll is the first from the Des Moines Register, together with CNN and Mediacom, to put the two-term Massachusetts Democrat in the lead, at 22 percent. Former vice president Joe Biden, who led the Register’s June poll, fell by 3 percentage points to a close 20 percent. And Sen. Bernie Sanders (I-Vt.) slipped 5 percentage points to a distant third, at 11 percent.
The poll was conducted Sept. 14-18 among 602 probable caucusgoers in the first-in-the-nation contest, which will take place in February. The margin of error is plus or minus 4 percentage points.