Lynn:  As soon as we adopt "preferential voting" it will make sense to support Third Party or Independent candidates.  Until then third party/independent candidates ALWAYS siphon off votes from the "two-party" candidate who positions are the most similiar.  Ralph Nader is the most recent and most significant example of this phenomenon.  I'm far from a "hard-core" Hillary fan and I voted for Bernie in the primary.  While to not support Hillary with my vote in November might feed my self-righteousness,  it would be counterproductive to my concern for the welfare of our country's future.  

All my life I've been a old-fashioned, FDR, working-class liberal....I continue to be.  IMO Hillary will, in every way imaginable, be a better choice for the welfare of today's and, importantly, tomorrow's America.  

Let's remember how Nader, directly violating his word, refused to drop out of the 2000 race and endorse Gore.. IMO, he valued his "purity"  over the welfare of America.  How about you?