After graduating from law school, Tribe clerked for Justice Mathew Tobriner of the Supreme Court of California from 1966 to 1967, then for Justice Potter Stewart of the U.S. Supreme Court from 1967 to 1968. He then joined the Harvard Law School faculty as an assistant professor, receiving tenure in 1972. Among his law students and research assistants while on the faculty at Harvard have been President Barack Obama (a research assistant for over two years), Chief Justice John Roberts, US Senator Ted Cruz, Former D.C. Circuit Chief Judge and Attorney General nominee Merrick Garland, and Associate Justice Elena Kagan. Other notable students of Tribe were U.S. Representative Adam Schiff, Chair of the House Intelligence Committee and lead manager for the first Impeachment of Donald Trump, and Jamie Raskin, lead manager for the second Donald Trump impeachment.