This is a complex subject. At the purely academic level, we question whether Jefferson was really Unitarian, and whether it makes sense to claim him by naming a district after him. However, that is not the reason for the un-naming - it is our reaction to the fact of his slaveholding and his relationship with Sally Hemings. Given the understandable depth of feelings on the issue, I concur in the the necessity and symbolic importance of the change in name.
But I am bothered by the triumphalism of some of those announcing the change. The editor of the UU Updates mailing list posted the link along with the cheery note, "The third time is the charm: Thomas Jefferson District changes its name." The District President said “This district has had more conversations and is further along at becoming multiracial and multicultural than any other district because of those conversations.” It's important to know who is most righteous among us. Humility has never been an important Unitarian virtue.
Having now washed away a spot on our soul, we can engage in self-congratulation, because unlike Jefferson, we do not persist in actions that we know to be wrong, and have nothing to fear from the judgment of those two centuries hence.
While in a different tone, we have these statements from Jefferson: "I tremble for my country when I reflect that God is just, that His justice cannot sleep forever... The whole commerce between master and slave … is despotism… Nothing is more certainly written in the book of fate than these people are to be free."
A Piece of Wisdom Literature (Luke 18:9-14)
To some who were confident of their own righteousness and looked down on everyone else, Jesus told this parable: “Two men went up to the temple to pray, one a Pharisee and the other a tax collector. The Pharisee stood by himself and prayed: ‘God, I thank you that I am not like other people—robbers, evildoers, adulterers—or even like this tax collector. I fast twice a week and give a tenth of all I get.’
But the tax collector stood at a distance. He would not even look up to heaven, but beat his breast and said, ‘God, have mercy on me, a sinner.’
I tell you that this man, rather than the other, went home justified before God. For all those who exalt themselves will be humbled, and those who humble themselves will be exalted.”An Afterthought
Some within Unitarian Universalism note that William Ellery Channing was deficient in his views on slavery. Maybe renaming the Ballou Channing District should be next?
A long statement by Jefferson on the moral problem of slavery: http://afgen.com/slavery3.html
A discussion thread on Beliefnet: ttp://community.beliefnet.com/go/thread/view/34789/27551361/Was_Jefferson_District,_now_Southeast