Poll: Biden supporters warm to Warren as an alternative

A new poll shows that former Vice President Joe BidenJoe BidenImpeachment week: Trump probe hits crucial point Trump DACA fight hits Supreme Court Juan Williams: Honesty, homophobia and Mayor Pete MORE’s supporters are starting to warm up to Sen. Elizabeth WarrenElizabeth Ann WarrenJuan Williams: Honesty, homophobia and Mayor Pete Trump DACA fight hits Supreme Court Democrats on edge as Iowa points to chaotic race MORE (D-Mass.) as a viable alternative, though Sen. Bernie SandersBernie SandersJuan Williams: Honesty, homophobia and Mayor Pete Democrats on edge as Iowa points to chaotic race Democrats debate how to defeat Trump: fight or heal MORE (I-Vt.) is still the preferred second choice. 

The Hill-HarrisX poll released on Monday found that 20 percent of likely Democratic voters who support Biden would support Warren as their second choice, which marks a 12-point increase from when an identical poll was conducted in May.

However, Sanders still remains the top second-choice candidate among Biden supporters at 35 percent, an 8-point increase from the May 3-4 poll.

Another 10 percent of Biden supporters said they would back Sen. Kamala HarrisKamala Devi HarrisJuan Williams: Honesty, homophobia and Mayor Pete Democrats debate how to defeat Trump: fight or heal Women who inspired 'Hidden Figures' film will be honored with congressional gold medals MORE (D-Calif.), a 5-point dip from the last poll. Former Rep. Beto O’Rourke (D-Texas) garnered 5 percent support, a 6 point fall. South Bend, Ind., Mayor Pete ButtigiegPeter (Pete) Paul ButtigiegJuan Williams: Honesty, homophobia and Mayor Pete Democrats on edge as Iowa points to chaotic race Democrats debate how to defeat Trump: fight or heal MORE (D) followed, dipping to 7 percent from 10 percent.

Other polls have shown similar results.

According to a weekly Morning Consult data tracker, 25 percent of Biden's supporters said they backed Sanders as their second choice, compared to 20 percent who chose Warren as their next favorite. Harris was named as the second option by 14 percent, according to the poll's latest figures that were updated last week. 

The survey comes as the Democratic primary heats up, though signs are emerging that the race is becoming a four-way race between Biden, Sanders, Warren and Harris.

The Hill-HarrisX survey was conducted among 138 Democratic and Democratic-leaning Biden supporters between Aug. 16 and 17 with a margin of error of plus or minus 8 percentage points.

—Tess Bonn