Ranking member

In United States politics, a ranking member is the most senior member of a congressional or state legislative committee from the minority party.https://web.archive.org/web/20110701083132/http://projects.washingtonpost.com/politicsglossary/Congressional/ranking-member/ 

When party control of a legislative chamber changes, a committee's ranking minority member is likely, though not assured, to become the next chairman of the committee, and vice versa.

References

Category:Politics of the United States