Longtime Rep. Barney Frank, D-Mass., announced Monday he is not seeking re-election, saying that redistricting has made it too strenuous to continue to campaign.

The 16-term lawmaker, whose name is emblazoned on the banking reform law that passed Congress last year, had long been rumored to be ready for retirement. He said Monday that he actually decided “tentatively” to retire after passage of the law, serving out one more term, but when Republicans won the 2010 midterm he decided he didn’t want to be a lame duck so didn’t announce his plans until now.