Although the 29th was (then as now) drawn as a majority-Hispanic district, Green finished second in the five-way Democratic primary, behind city councilman Ben Reyes.

In the 115th Congress, Green was the only non-Hispanic white Democrat representing a significant portion of Houston, and one of only three in the entire Texas delegation (the others being Lloyd Doggett and Beto O'Rourke).

Since being elected to the House of Representatives, Green had been working on education, labor, energy, domestic manufacturing, health issues, NASA's Johnson Space Center, and Social Security and veterans benefits.

Green voted in favor of the Iraq Resolution in 2002, and gave a speech on the house floor linking Saddam Hussein to the September 11 attacks in 2001.

Despite the Democratic leadership's general disapproval of the war, Green voted against measures aimed at placing a timetable on military withdrawal.

Green also served on the Energy and Commerce Committee's Subcommittee on Health during drafting of the Affordable Care Act of 2010 and helped write and amend the legislation.