Progressive Sen. Elizabeth Warren, D-Mass., on Monday endorsed far-left candidate Abdul El-Sayed in the Michigan U.S. Senate Democrat primary, deepening the ideological divide within the Democratic Party ahead of one of the year's most closely watched midterm races.

"I'm endorsing @AbdulElSayed today—because he is THE fighter Michigan needs in the Senate," Warren wrote on X.

El-Sayed, a former public health official, welcomed the endorsement, praising Warren as "a generational voice" against corporate influence in politics.

"Michigan needs unbought, principled leadership, and with Senator Warren's support, we can get rid of the chokehold that corporations have on our government," El-Sayed posted on X.

Warren's endorsement gives El-Sayed another major progressive ally after endorsements from Sen. Bernie Sanders, I-Vt., and Rep. Alexandria Ocasio-Cortez, D-N.Y., both of whom campaigned with him in Michigan over the weekend, Politico reported.

The endorsement battle underscores a broader fight for the future of the Democratic Party.

El-Sayed is challenging Rep. Haley Stevens, the candidate backed by retiring Sen. Gary Peters and Senate Minority Leader Chuck Schumer, D-N.Y.

Warren praised El-Sayed's platform and highlighted his refusal to accept corporate PAC money while criticizing the millions of dollars in outside spending benefiting Stevens.

The race has become a proxy battle between the Democrat establishment and its increasingly influential progressive wing.

The New York Times reported earlier this month that Ocasio-Cortez's endorsement marked her first contested Senate primary endorsement of the 2026 cycle, putting her directly at odds with Schumer over who is best positioned to hold the battleground seat.

Republicans have pointed to El-Sayed's record as evidence that Democrats are moving further left.

In April, Politico reported that El-Sayed declined to distance himself from controversial left-wing streamer Hasan Piker, who has faced widespread criticism for saying America deserved the Sept. 11 terrorist attacks and claiming Israel has no right to exist.

El-Sayed dismissed calls to condemn Piker's comments as a "gotcha game" and argued Democrats should embrace progressive online personalities rather than distance themselves from them.

El-Sayed also has drawn scrutiny for previously supporting "Medicare for All," advocating to abolish ICE during an earlier campaign, and embracing other progressive policies that Republicans argue are out of step with many Michigan voters.

The Aug. 4 Democrat primary will determine who faces former Republican Rep. Mike Rogers in November.

The open seat, created by Peters' retirement, is viewed as critical to Democrats' hopes of regaining the Senate majority, making Michigan one of the most competitive races of the 2026 midterm elections.