I'm not American but I think this question is interesting, I have voted for a variety of left wing parties and while I've heard a lot which has influenced my political opinion, or rather clarify them for me, I definitely have never heard anything which has influenced my vote.
I havent ever voted "against the grain" (always left wing, sometimes irish nationalist/community background votes), even when I've been told it would be a good tactical move. I wouldnt often vote for a moderate, against a militant candidate I support, in order for a moderate to win against a moderate or militant opponent of another political persuasion.
This said I'm beginning to think that there's been more and more of a political consensus globally within the UK and NI and ROI, a convergence, it is a total alternative to the so called "liberal consensus" which Thatcher and Reagan believed they had overthrown, I didnt really consider that a consensus or a liberal one, in any sense of the word liberal. I think its true that there were political conservatives prior to Thatcher who were interested in the politics uber economics or personal interest or their core constituency of rich special interests but I think even they were inclined towards many of the destabilising changes for reasons of background that Thatcher and Reagan were.
Although now I think there is just a self-serving cross party elite, there's neoliberal capitalism and neoliberal capitalism lite, often not even lite, just another brand like Pepsi and Coca Cola but even more than that the political bosses want to be political bosses and nothing more, that's why the vote through massive tax funded kick backs to friends in the city and then provided with reprieves from instability in the economy for long enough they vote themselves massive pay rises, which they in turn go back to their buddies in the city to try and invest for personal gain. This is how and why privatisation and any other political policy dreamt off will never improve or simply maintain existing services, its not even for that purpose. Its all about funnelling massive amounts of public money into private pockets, a little for themselves a lot for their paymasters in the city.
Anyway, I think that of the mainstream parties the supposedly "left wing" ones the world over ARE the moderate, "reasonable" face of neo-liberalism, the so called conservatives are the former militant tendencies of the same parties. I think the militant tendencies of the left wing still exist, they are relics for the most part, a mix of naivette and lunacy. So there's no way I'd vote for the "other side", it sickens me enough to have to vote for the supposedly left wing parties.