I have not been a fan of the modern GOP. I see today's GOP as the party of torture, corruption, thoughtless bellicosity, cynical manipulation of American fears and hatreds, bad policy, anti-science, anti-reason, and so on. I also disagree with most GOP values, though my support for abortion rights is unenthusiastic.
And so, when a good person and a friend writes asking when I might join the "sane" party, I am taken aback. My Dems are often (mostly?) corrupt, pompous and venal - but I do think of them as the saner party. How can good people feel the GOP is the sane alternative? It is suspiciously convenient to say these people are delusional. Instead I'll try to examine their beliefs along four chasms - Facts, Values, Faith and Tribe. I think I can understand their beliefs best in those terms.
Facts
Not everyone obsessively follows hundreds of blogs and uses selected super-readers as fact filters. More reasonably, but unfortunately, not everyone reads
factcheck.org. If you live in some parts of the country, and if you don't read online news or the New York Times, you will be told many things that are not true. More perniciously, you won't hear of anything that might change your perceptions.
If you believe the chain letters, or the WSJ OpEd page, or Murdoch's newspapers, you may well believe the Democrats are insane.
This seems like the easiest canyon to bridge. Facts, after all, can be tested. Predictions can be falsified. In reality, however, Vulcans are few. People may be attracted false facts because they support three other chasms.
Values and culture
What do the strong owe the weak? When do the ends justify the means? What are the limits to tolerance? What far can Americans move from a cultural mean?
These are fundamental differences. A good and generous person may feel they owe nothing to the weak save what they choose to give. That person is a natural supporter of the GOP. These are legitimate distinctions
Faith
We usually think of Faith in terms of Deities, but there can also be a Faith in Markets. Faith, by definition, is not amenable to discussion. If you believe the true duty of all men is to serve a particular deity, then your first political choice must be to support the Party closest to your deity. If you believe that Markets are infallible, then you must support a Party that shares your belief.
The chasm of Faith is a legitimate distinction between the GOP and the Democrats. Even religious Democrats tend to accept theological tolerance -- even when that tolerance is theologically inconsistent. The GOP has a much stronger claim to the Christian fundamentalist vote.
Tribe
Humans support their Tribe. It is especially hard for a member of a powerful Tribe to see its time is passing. The GOP is the Party of the White Tribe, and in particular of the White Male Tribe. The Democratic Party has a much blurrier Tribal identity, but if you're non-White or Gay or Lesbian it's a natural home.
The GOP and Dems are separated by chasms of Fact, Faith, Values and Tribe. The chasm of Fact seems easiest to cross, but often choices of Fact serve needs of Faith, Values and Tribe. Good persons, by reasons especially of Faith, Values and Tribe, may feel my party is less than sane.