"THAT SAID, it is clear that their ideal of a well-regulated ( and disciplined ) militia was well-nigh unachievable.
"Complaints abound during the Revolutionary War about desertions, laxity and unequipped troops."
Of course. It was common knowledge that professionals tend to make better soldiers than amateurs. But it was also understood that professional soldiers end up becoming a burden on the people, and end up abusing the people. That is why they were opposed to a standing army, and in favor of the public being armed.
They knew that amateurs could not beat professional armies 1 to 1 on an open field of battle, but they knew that amateurs could outnumber professionals, and could defeat them in detail. The Southern Campaign proved the worth of militias. The occupying armies could conquer and keep every city, but they could not control the countryside. When their troops went out to get supplies, they did not come back. They were defeated by small groups and even by individuals - all amateurs.
You are correct about racist undercurrents in some attempts at gun control, especially in California in the 1960s and 1970s. On the other hand, the NRA supported Robert F. Williams in North Carolina in his clashes with the Klan, and the supposedly racist South has been a bulwark against gun control in the modern era, even though the population of Southern states is typically about one third black. (Gun control laws originated in the South to prevent the possibility of a slave rebellion, but this was in reaction to the slave rebellion and genocide of white and mixed-race persons in Haiti.) Without the fear of slaves revolting and murdering their neighbors, and as long as it is about self-defense and maintaining an orderly and lawful community, Southerners seem to be pretty comfortable with black people having weapons. It does doubtless help that black groups with clearly communist ideologies have not been doing much demonstrating in the South.
As for modern groups, the Oath Keepers provided security for black protesters in Ferguson. I have also seen very positive coverage of the Huey P. Newton Gun Club (in Texas) from conservative media. Most conservatives seem fine with minorities being armed for their self-protection, though they draw the line when it comes to groups advocating murder or theft. How does that fit the "racist" narrative?