Rep. Dan Goldman unseated by Mamdani-backed Brad Lander

Rep. Dan Goldman (D-N.Y.) was unseated in his Democratic primary Tuesday night by former New York City comptroller Brad Lander, according to the Associated Press.Why it matters: Lander's victory — fueled in part by support from New York Mayor Zohran Mamdani — represents the latest in a string of victories for the left in Democratic congressional primaries.Progressives from California to Maine have harnessed liberal grassroots anger towards the Democratic establishment to topple party-backed foes and incumbent House Democrats.Despite being a Progressive Caucus member, Goldman came under fire in his left-leaning district for his staunch support of Israel.Zoom out: Lander ran for New York mayor last year but failed to gain traction, instead becoming part of Mamdani's orbit after cross-endorsing the then-state legislator in an effort to defeat former Gov. Andrew Cuomo.Lander channeled the resultant goodwill from the left into a run against Goldman, touting himself as a liberal Zionist who will be more critical of the Jewish state in Congress.Between the lines: The race pit Mamdani against House Minority Leader Hakeem Jeffries (D-N.Y.), who supported Goldman as part of his policy of generally supporting his incumbents.Goldman is the third Democratic House incumbent unseated in a primary this year after Reps. Al Green (D-Texas) and Julie Johnson (D-Texas).He may not be the last, however, with numerous older and more moderate incumbents facing primaries from younger or more left-leaning insurgents.