MSNBC contributor and Swing Left adviser Emily Tisch Sussman said supporting Sen. Bernie Sanders (I., Vt.) over Sen. Elizabeth Warren (D., Mass.) for the Democratic presidential nomination might be "showing your sexism."
Sussman told MSNBC host Craig Melvin on Monday she overheard what she thought was "an interesting point" about Sanders supporters.
"Basically at this point if you are still supporting Sanders as opposed to Warren it's kind of showing your sexism," Sussman said. "Because she has more detailed plans and her plans have evolved. I thought it was an interesting point and I think there may be something to it."
Melvin asked Sussman if Sanders had "peaked" in Iowa after a new poll showed Warren overtaking former vice president Joe Biden to lead the pack of Democratic candidates.
"It does feel that way," Sussman responded. "It feels like Warren is pulling together a coalition of people, particularly women, and also people of color, who liked Hillary Clinton."
She also argued Warren is pulling support away from Sanders, saying the Vermont senator's support has a hard ceiling.
A recent Des Moines Register/CNN/Mediacom poll showed Warren surging into first place in Iowa with 22 percent support, ahead of Biden's 20 percent. Sanders's support declined to 11 percent, putting him in a distant third place ahead of South Bend mayor Pete Buttigieg's 9 percent.
The poll also indicated left-wing voters favor Warren over Sanders. Of Iowa caucus goers who identify as "very liberal," 48 percent said they support Warren while just 20 percent said they back Sanders.
Warren's surge comes in the midst of turnover within the Sanders campaign. The campaign confirmed last week it had parted ways with its Iowa political director, as well as a senior adviser in New Hampshire.
Sanders's campaign manager dismissed the polling as "inconsistent," according to the Washington Post. Sanders is embarking this week on a "Bernie Beats Trump" tour across Iowa.