Rep. Steve King: John Lewis hasn't contributed since civil rights work

Iowa Rep. Steve King has one question for Georgia Rep. John Lewis: What have you done for us lately?

Lewis told an Iowa radio station, "I have long contemplated just going to the floor and saying, 'John Lewis, thank you for your contribution to civil rights during the civil rights era. I would appreciate if you'd contribute something since then. It's been a half a century.'"

King was also critical of the Congressional Black Caucus, saying, "When they formed the Congressional Black Caucus back years ago, in the aftermath or in the beginning of the civil rights movement, the shape of that, I looked at that even then and I thought, 'How can you form a caucus that's established on race?' But they did, and they got away with it because people didn't want it challenged. And now, the Congressional Black Caucus, I just openly say they're the self-segregating caucus."

SEE MORE: Marco Rubio, Elizabeth Warren Weigh In On The Trump-Lewis Feud

Lewis recently told NBC News he doesn't consider President-elect Donald Trump a legitimate president, prompting backlash from Trump and his supporters.

Lewis is an icon of the civil rights movement, famous for leading a 1965 march in Selma, Alabama, that ended in a brutal police crackdown.

More recently, Lewis sponsored the House version of a bill to re-investigate some unsolved racially motivated crimes committed before 1980. President Obama signed that bill into law in December.

King has something of a history of wading into racially charged issues.

During an interview on MSNBC, he asked, "Where are these contributions that have been made by these other categories of people that you're talking about? Where did any other subgroup of people contribute more to civilization?"