A large part of the problem is in deciding which information sources to trust. My father gets much of his information from his investors' newsletter, and you can probably predict the bias inherent in that! I'm constantly having to undo some of the things he "learns", but the good news is that sometimes I succeed. I got him to watch An Inconvenient Truth, and it influenced him. He sometimes backslides on it, but in general, I think he's sympathetic to my environmental concerns. In addition to choosing what sources to read, one's biases also determine what we remember and how we process the information we receive. Do we decide some bit of evidence is the exception or the rule? In general, we humans aren't designed for the informational landscape that we now inhabit, and it's not just Republicans that have this problem.

My answer would be yes.  I see that as actually a good thing.  If the answer were no, things would be bleaker.  Republicans have different understandings of how the world works in some cases, different values and beliefs in others, and of course their own unique personal histories which contribute to how they see the world.  They are actually human--of this I am quite sure.  Most of the time.  I'm sure the Republicans wonder the same about us.  

stillidealistic was a Republican until not too long ago.  I wonder how she would answer your question.  She's told her story at the cafe.  It's a good one, too.  I would bet there are other former Republicans out there, maybe just lurking.

People do sometimes change their minds about some things they'd held onto for a long, long time.  The process of trying to persuade others on political matters is typically slow and uncertain.  I would doubt there are many at dag who have never experienced some pretty strong frustration at the inability or unwillingness of someone they're discussing something with to "see the light".   Obviously including here, in exchanges at dag itself. 

I don't think facts and sound arguments are irrelevant, although it can feel that way sometimes.  If more of us ordinary folks keep working at informing ourselves and getting better at making the arguments...well, that's one way change happens, at the personal and local levels.  Being able to represent and advocate what we believe in a way that generates respect, maybe even further thought, in another person (not necessarily at the time of the conversation) is part of change processes.  My reply here might seem pretty emotionally flat but believe me, if this isn't obvious from what I write here, I'm exasperated with all the craziness going on around us, too.  My two pennies.

It seems to me that if you have an annual income below $250k you are a deluded moron to vote Repugnant.

YES

"Is there such a thing as a sincere, well informed, non-venal Republican?"

NO.

"It seems to me that if you have an annual income below $250k you are a deluded moron to vote" Republican. 

TRUE.

" ... convince me, then ...that these benighted people are susceptible of change, that they can be reached." 

THEY AREN'T AND THEY CAN'T BE.

Wow, that was an easy test.  And for those that would say, "Well gee, Mr. Smith, you're being an idiot because we need to keep reaching out to the good people in the GOP and try to win the day with our ideas", I would say, that we would do better to build a series of roach-like "Republican Motels" and place them in the corners of every bank, brokerage house, Bob Evans restaurant, and NASCAR venue in America, so that all the GOPers will check in, but they won't check out. Then all we have to do is toss them all into a big dumpster and bury them in a landfill in New Jersey.  Yes, I'm that freaking angry and disgusted, and feeling completely hopeless,  But I've had it up to here with trying to be reasonable, cajoling, nice, logical, appealing to the better angels of their nature, etc., etc.  What's ... the ... point? They will simply come in with their big money, and voter caging, robo-calling, voting machine tampering tactics, and steamroll us all into oblivion and then, when the average GOPers allegiance to the rich and the big corporations, (which they thought was going to save them from the same fate as us Democrats), betrays and destroys them too, they will simply shriek at us for not doing more to save them. It's a never-win situation.  So, perhaps it IS time to let it all burn to the ground. Perhaps it will take destroying everyone and everything to bring the lower and middle classes together and let them see and feel their complete enslavement by the rich and powerful corporations that are strangling the very life-breath out of America. Maybe some people need to learn that when they have nothing, they have nothing to lose.  But us Democrats also need to learn that in the custom toilet business, there are no reasonable assholes.   

The Republicans have done an excellent job of combining the the economic agenda of the ruling class with the social agenda of many groups who seek power to do their thing and see the GOP as a resource. In addition, there a great number of people who think the best chance they will have of furthering their own opportunities is when that aforesaid agenda is allowed to generate a lot of wealthy consumers.

Venn diagrams could represent how these different elements overlap or not in the world views of Republicans. Limbaugh's job is to make the organized efforts of the ruling class to maintain this overlap appear to be desperate attempts to stave off the hordes of hippies relentlessly plucking at the fabric of this nation.

But since you are looking for the group that is not totally stoned out of its mind, I suggest concentrating on those who think they have cut the best deal for themselves by reducing their taxes and paying for what used to be part of  the public weal on a strictly demand basis.

Add to this the fact that without government having the power to rescue markets when they threaten the collapse of the entire economy, we would be all in an apocalyptic hell-scape right now, the Republicans you might engage with have to start talking about governance that is strong enough to create fair markets.

In other words, if the government is to have enough power to do the things Republicans want, that government will need to be liquid.

Money talks, bullshit walks.