"The presidency is not an entry-level position," the paper wrote. "Whoever is sworn into office next January must demonstrate not only a deep understanding of the issues facing America, but also possess the diplomatic skills that enable presidents to forge alliances to get things done.
"By that measure, Democrats have one outstanding candidate deserving of their support: Hillary Clinton. No other candidate can match the depth or breadth of her knowledge and experience."
In endorsing Florida Senator Marco Rubio for the Republican nomination, the editorial board of the Register wrote that Rubio "offers an uplifting message of a 'New American Century."
"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 register wrote on Jan. 24. "We endorse him because he represents his party's best hope."
The endorsement comes at a crucial time in the race, with former Secretary of State Hillary Clinton holding only a small lead over Vermont Senator Bernie Sanders in Iowa. According to RealClear Politics, Clinton averages at 47 percent to Sanders' 41 percent, with the gap between the two candidates growing smaller in recent weeks.
The CNN/ORC poll, the most recent poll of Republicans in Iowa, shows Rubio coming in third in the state with 14 percent of likely Republican voters saying they would vote for him if the election were held today. Donald Trump had 37 percent support in the same poll, and Texas Senator Ted Cruz had 26 percent.