Here are the key primary election results from Iowa
Seven states hold primaries Tuesday: California, Iowa, Mississippi, Montana, New Jersey, New Mexico and South Dakota.
In Iowa, retired U.S. Navy Adm. Michael Franken has won the Democratic nomination for U.S. Senate, easily beating former U.S. Rep. Abby Finkenauer. Franken now faces an uphill battle against longtime Republican U.S. Sen. Chuck Grassley.