James Thompson came within five points of winning a Kansas congressional seat in a district that went for Trump by 27 points. He did so by getting almost no support from the national Democratic establishment. His success -- and given the odds stacked against him, the success was considerable -- was based on him articulating a clear message in support of policies that would help the people in his district and against policies which would harm them.
In this interview with ThinkProgress, he implores the Democratic establishment not to ignore Democratic candidates in seemingly safe Republican districts because every district -- every single one -- can be won by a strong candidate sending a clear message.
The district in which I live, currently represented by Pat Tiberi, was seemingly tailor made for him and is likely considered "safe" for Republicans. But Donald Trump certainly did not win the 12th by 27 points and Pat Tiberi has decided that falling in with Trump's agenda is, somehow, a great idea. He has decided to promote policies which are bad for people in his district. Policies which will do them harm.
Pat Tiberi can be beat. Any congressman in any district, no matter how seemingly safe the district is, can be beat. Do not write their challengers off and do not let the Democratic Party do so either.