Sen. Tom Harkin (D-Iowa). washingtonpost.com

Sen. Tom Harkin (D-Iowa) announced Saturday that he will not be seeking reelection in 2014, presenting Democrats and Republicans with key tests of their midterm electoral strategies.

Harkin made the announcement and met with supporters and party activists before making calls to reporters from Des Moines. Here's what he told The Washington Post's Ed O'Keefe: