Rand Paul also does better than all other R nominees when it comes to independents. It may be his moderate views on drugs and foreign policy. One thing is for certain; it will be a challenge to cast him as some right wing loon.
Justin Amash, about as pure a libertarian as there is in the House of Representatives, is in a political fight with a well-heeled Republican who is more blatantly an authoritarian right-winger in the primaries. Amash seems to be running for his political life in Michigan (greater Grand Rapids, a swing area in Michigan).
Libertarians get almost no crossover support from liberals, especially minorities and union members who are much of the Michigan Democratic Party.
Hillary Clinton has the Obama coalition locked up in Michigan. The state usually looks close before Labor Day, after the which the unions and minorities start organizing.
