While the editorial praised both Romney and Obama, the decision ultimately came down to one question: who can resuscitate the stumbling economy?, the newspaper said.
"Which candidate could forge the compromises in Congress to achieve these goals? When the question is framed in those terms, Mitt Romney emerges the stronger candidate."
According to the announcement, the editorial board, which enthusiastically endorsed Romney ahead of the state's Republican presidential caucuses in January, had "a vigorous debate" over which candidate to choose for the November 6 election.
While "Romney has made rebuilding the economy his No. 1 campaign priority," the paper stated, "the president's best efforts to resuscitate the stumbling economy have fallen short. Nothing indicates it would change with a second term in the White House."
The editorial board said the country needed a "renewed sense of confidence" in the economy. "That should come with Mitt Romney in the White House."
With six electoral votes, the swing state is highly contentious territory in the tight presidential race. The president campaigned in the Hawkeye State on Wednesday, while Romney was also in the state Wednesday, as well as Friday.
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An NBC News/Wall Street Journal/Marist poll released last week indicated Obama was ahead of Romney by 8 points, 51 per cent to 43 per cent, while a separate American Research Group survey released days earlier showed the two candidates tied at 48 per cent.
Obama frequently points to Iowa as the state that launched him on the path to winning the Democratic nomination in 2008.
Earlier this week, the paper blasted the Obama campaign after the president sat down with the editorial board for an interview on Tuesday but refused to go on the record.
The Des Moines Register endorsed Obama in 2008 and Senator John Kerry in 2004. The last time it backed a Republican was in 1972 with its support for Richard Nixon, CNN reported.