Republicans in Iowa have narrowed the party-registration edge enjoyed by Democrats in that state. 

Iowa Secretary of State Michael Mauro said Tuesday that as of July 1, registered Democrats in the state outnumber Republicans by some 55,000. At the beginning of the year, Democrats held a voter-registration advantage of nearly 100,000.    

The shift is mostly a result of last month's competitive Republican primary for governor. Mauro said some 47,000 voters switched their registration so they could vote in the GOP primary. 

“Based on what I’ve seen as an election official, it’s really difficult to draw any definite conclusions about this year’s numbers and how it will impact [the] elections this fall,” Mauro told Radio Iowa. “But clearly the primary did have an impact on the political landscape here in the state.”