The Des Moines Register announced Saturday night that its editorial board is backing Clinton for the Democratic nomination and Rubio for the Republican nomination. The endorsement comes as Clinton faces a tight race with Sen. Bernie Sanders in the Hawkeye State and Rubio trails Donald Trump and Ted Cruz in the polls.
"Democrats have one outstanding candidate deserving of their support: Hillary Clinton," reads the endorsement for the former secretary of state. "No other candidate can match the depth or breadth of her knowledge and experience."
The endorsement was not without caveats, however.
"She is not a perfect candidate, as evidenced the way she has handled the furor over her private email server," the editorial board writes.
The paper hailed Rubio as the candidate most likely to "chart a new direction" for the Republican Party.
"Sen. Marco Rubio has the potential to chart a new direction for the party, and perhaps the nation, with his message of restoring the American dream," the endorsement reads. "We endorse him because he represents his party’s best hope."
The editorial board also writes: "Yes, we wish the first-term senator had greater experience. Yes, we wish he followed the lead of colleague Chuck Grassley and rarely missed a vote in the Senate."
The Des Moines Register has never endorsed a Democrat that went on to win the Iowa caucus and party's nomination (in 2008, it endorsed Clinton), but since 1996 the paper has endorsed the GOP candidate who become the nominee.
Clinton was working the rope line at her "Hard Hats for Hillary" event in Davenport, Iowa, just as her endorsement by the Des Moines Register was announced.
"I'm very pleased, obviously," she told reporters. "It means a lot."
ABC News' Liz Kreutz and Josh Haskell contributed to this report.