Conversation so far:
Who was Mike Gravel's running mate in the 1972 election?
Who did Mike Gravel compete against in 1972?
Mike Gravel was not alone in this effort, as former Governor of Massachusetts Endicott Peabody had been running a quixotic campaign for the same post since the prior year.
What significant events happened during the 1972 campaign?
McGovern announced Senator Thomas Eagleton of Missouri as his vice-presidential choice. Eagleton was unknown to many delegates and the choice seemed to smack of traditional ticket balancing considerations.

Question: What did Gravel do afterward?
Self-contained rewrite: What did Mike Gravel do after George McGovern announced Thomas Eagleton as his vice-presidential choice?