LINCOLN -- Omaha attorney Dave Domina has won Nebraska's Democratic primary election for U.S. Senate. Domina easily defeated Larry Marvin of Fremont in Tuesday's primary race. He will face the winner of the Republican primary in a contest to replace Republican U.S. Sen. Mike Johanns, who is not seeking a second term. The GOP enters the race as a strong favorite in conservative Nebraska. Domina is best known for his opposition to construction of the Keystone XL oil pipeline. Marvin is a part-time assistant foreman at a Fremont meatpacking plant who had raised no money and not actively campaigned.