SAN FRANCISCO (KPIX 5) — A new CBS News/YouGov Tracker poll of early primary states shows Massachusetts Senator Elizabeth Warren leading the pack of Democratic presidential candidates, thanks in part to former Kamala Harris supporters.

Warren polled with 26% support, compared to former Vice President Joe Biden’s 25% and Vermont Senator Bernie Sanders’s 19%.

This represents a six point jump for Warren, a four point jump for Sanders and no movement for Biden. California Senator Kamala Harris’s support dropped from 16% in July to 8% in the current poll; about a third of the voters who moved away from Harris are now supporting Warren.

The poll surveyed 7,804 registered voters who are Democrats or Independents who lean Democrat in 18 early voting states, from the Iowa caucuses to Super Tuesday, which includes California. (The margin of error is +/- 1.8%.)

“This is a story of Elizabeth Warren rising, not necessarily Joe Biden falling,” said Anthony Salvanto, Director of CBS News Surveys and Elections. “He is about where he has been.”

Biden’s support may not have changed, but CBS projects it’s worth 600 delegates. Warren may be ahead by one point, but she’s projected to have 545 delegates. For Sanders, it’s 286 delegates.

As for Warren, “her support and that boost she’s getting is a result of other candidates’ now-former supporters moving to” her camp, especially Harris.

“Her supporters are now moving to Elizabeth Warren at twice the rate that they’ve moved to Joe Biden and to other candidates.”

CBS/YouGov pollsters have followed up with thousands of prior survey respondents and estimate that, of the total number of voters who have stopped supporting Harris, 29% have gone to Warren and 15% have gone to Biden.

The Wall Street Journal reports that Harris’s campaign team had a special meeting with donors on Friday and said it is, “ramping up its organization in Iowa and South Carolina in particular.” Since 1972, every candidate for president from a major party has come in first or second place in either Iowa or New Hampshire.

The new polls shows Warren (27%) and Biden (26%) leading in New Hampshire, and Biden (29%) and Sanders (26%) leading in Iowa. Harris is in fifth place in both states, behind the three frontrunners and South Bend, Indiana mayor Pete Buttigieg.