(CNN) - Democratic Rep. Raul Grijalva has won a fifth term in the U.S. House after narrowly defeating Republican Ruth McClung, a physicist, according to a CNN projection. Grijalva prevailed with 49 percent of the vote, compared to 45 percent to McClung.
The Arizona Democrat found himself in an increasingly competitive race after he announced his support of a boycott of Arizona businesses in response to the state's controversial new immigration law. McClung was heavily out-raised and out-spent but received the backing of prominent state Republicans, including Gov. Jan Brewer and Sen. John McCain, as well as from former vice presidential nominee Sarah Palin. President Obama carried the district 57 to 42 percent in 2008.
Nine other U.S. House races remained unresolved, all in districts currently held by Democrats. Republicans had a net gain of 60 seats as a result of Tuesday's midterm election.