I mostly agree with your assessment of the Charleston killings. However I'm much more optimistic than you seem to be on the state of race in the US. After all, the response in South Carolina, (Governor is a female of Indian descent, one of the Senators is of African descent, both Republican, by the way) was quite strong and swift. The killer was found, will be charged and probably put to death or put away for a very long time. This is a much different reaction than would have taken place 60 years ago. I don't see how the reaction to this killing will, "risk losing all of the ground we have made as a country over the past 50 years," as you say. And I think you have it backwards, the youth won't take cues from their leaders. On this issue all politicians will fall in line behind public opinion and public opinion is overwhelmingly consistent with many of the thoughts you expressed.
There was one major issue I have with your letter, and maybe it's a problem with your source, The New York Times. You are outraged by the reactions of Rick Perry, Rick Santorum, Mike Huckabee and Bobby Jindal. I have no particular positive or negative thoughts towards Jindal or Perry and think Santorum and Huckabee are only slightly removed from the clownishness of Trump. I happened to be listening to a podcast yesterday and heard Bobby Jindal's reaction to the shooting. It was far from the reaction painted by the Times. So I did a cursory search for his reaction. This is what I found.
From The Blaze:
“It doesn’t matter if you are black or white,” Jindal said. “It doesn’t matter if you are a Republican or Democrat we can all agree that nine people gunned down in a Bible study in a church, a house of God this evil, evil individual said he spared the life of one of those individuals so he could go and tell others what he has done.”From The New Orleans Times Picayune
Gov. Bobby Jindal on Twitter: "Every American needs to take a few minutes today, and in the days to come, to pray for the families of those murdered last night." He also said on a Twitter posting: "I'm enraged by this ungodly act and my heart breaks for these families. I hurt for them."From Talking Points Memo
"I don't think we have words strong enough to describe how evil this is," Jindal responded. "Whatever words you want to put on to it. This man went into — from what we've heard, he goes into a church, sits there for an hour like you said, kills nine people and then says to some of the survivors 'I'm letting you live so you can go tell people what I've done.'"
"In my mind, look, there are no words strong enough to condemn that," he continued. "Evil, terror, whatever we want to call it. This is horrific. It's almost unimaginable."
As I said, I have nothing particularly positive or negative to say about Jindal, but it is curious the New York Times has an unattributed statement from Jindal that is completely different than every other statement even a cursory search revealed.
What's wrong with the New York Times?