[2] He graduated from William Chrisman High School in 1982 and in 1986 received his Bachelor of Arts in political science magna cum laude from University of California, Santa Barbara, where he was a member of the Phi Delta Theta fraternity.

Among his court victories was a case on behalf of the National Organization for Women, which required all California State University campuses to comply with Title IX.

[5] Huffman won the Democratic nomination for the 6th district, an open seat after incumbent Joe Nation was termed out, in a hotly contested June 2006 primary in which he surprised the political establishment with a victory over Pamela Torliatt, a Petaluma city councilwoman, and Cynthia Murray, a Marin County Supervisor who was initially considered the front-runner.

Huffman also defeated Assistant State Attorney General Damon Connolly, Marin County Democratic chairman John Alden, and sociologist Alex Easton-Brown.

[8] He defeated Republican nominee Robert Stephens in the general election[7] with more than 70% of the vote—the highest winning margin of any candidate on the ballot in the North Bay that year.

[9] In 2008, he sponsored a bill (AB 2950), which he wrote with internet attorney Daniel Balsam, that aimed to close what its proponents characterized as loopholes in the CAN-SPAM Act that made it more difficult to bring lawsuits against deceptive spammers.

[13] Upon his swearing-in on December 4, 2006, Assembly speaker Fabian Núñez named Huffman chair of the Committee on Environmental Safety and Toxic Materials.

After 20-year incumbent Lynn Woolsey announced her retirement, Huffman entered the race to run for her seat in the 2nd district, which had been renumbered from the 6th in redistricting.

[26] For the 118th Congress:[27] Huffman opposed the overturning of Roe v. Wade, calling it "sad, outrageous" and saying, "it's going to be tragic for millions of women in this country.

[33] On November 2, 2023, after Hamas operatives had stormed into Israel four weeks earlier, killing about 1,200 people and taking hundreds of hostages, Huffman joined only 22 other Congressmembers in voting against H. Res.

[34] After receiving swift criticism from Jewish American groups and other constituents, several days later Huffman disavowed his vote and issued a public apology.

[36][37] Huffman warned that the Project 2025 agenda would hit "like a blitzkrieg" (a "lightning war") and that lawmakers would need to be prepared to tackle it well in advance.

[36] He described Project 2025 as "a wrecking ball against everything that most of us hold dear about our country and our democracy,"[37] adding "that's the biggest challenge we face ... How do you explain that this really is what they're going to do without overwhelming people?