I suppose you'd get some REAL and rational answers from James McCarville & wife, Mary Matalin!.....but, they probably aren't available right now. Then there's my husband and I, who are pretty much polar opposites, politically....and well, frankly, we have very few shared opinions and we get along famously, have a great relationship.
My close friends are all over the map.....some who share my views and others who fiercely defend their views, others who have no clue which direction to lean toward.nor do they care... lol....
IMO, If you have enough things in common and a bond of friendship, certain topics, once opposing views have been established, don't need to be discussed. When my friends and I do get into any sort of political debate, we will simply express an opinion and an explanation as to why we might hold that opinion. End of discussion.
We can and DO agree to disagree. No problems. No hard feelings. Mature, intelligent adults can have friendships with people of all varying differences.
I wouldn't even think of defending my political views at the possible cost of a close friendship. That's fairly ludicrous. and THIS is a very interesting question, Susan....!