OMAHA, Neb. — Denise Powell won the Democratic primary in Nebraska’s 2nd Congressional District on Wednesday in a contest focused on the state’s “blue dot” status in presidential elections. The Omaha-area district, where Republican U.S. Rep. Don Bacon is retiring, is one of Democrats’ biggest targets this midterm season. It’s also a national focus every four years in presidential contests because Nebraska is one of just two states that splits its electoral votes. The 2nd District has gone to Democratic presidential candidates three times since 2008 — a “blue dot” in an otherwise sea of red. Powell, a political activist, defeated state Sen. John Cavanaugh and several other Democrats in a close race that could not be called Tuesday. She will face Brinker Harding, an Omaha City Council member endorsed by President Donald Trump. He ran unopposed in Tuesday’s primary.…