Nebraska Democrats are bullish about Republican losses in the right-leaning Plains state – but their prospects depend on today’s Democratic primaries, which include accusations of planted candidates and inadvertently depriving Democrats of power. A crowded Democratic primary in the state’s second congressional district, referred to as its “blue dot”, has focused around concerns that if a state senator wins, the Republican governor will replace him with a Republican who would help overturn Nebraska’s divided electoral college vote system. The district – which includes the state’s largest city, Omaha – is seen as a top contender for a Democratic pickup as the left works to win back the US House of Representatives during a midterm elections cycle expected to be bruising for Republicans.…