AL.com: Alabama law blocks 1 in 13 adults from voting
Danielle Lang is an attorney in the case and the deputy director of voting rights at the Campaign Legal Center, a Washington D.C.-based firm that's providing lawyers for the suit.
"I can find no other state that lacks the clarity about who has the right to vote, and that leaves the decision about who has the fundamental right to vote to the discretion of any number of individuals county by county the way Alabama does," said Lang.
The suit also argues that the state's requirement that all fines and fees associated with a conviction be paid before voting rights are restored constitutes a "modern day poll tax."
"Ms. Thompson has only one conviction in her whole life, for a theft crime, and owes $43,000 in restitutions, fines and fees," said Lang. "So for a woman who is scraping by on minimum wage jobs, trying to support her family, realistically she's never going to be able to pay back that amount. Even if she goes through the process of trying to restore her rights, she still couldn't (vote).
"The wealth of people should not determine whether they can get the right to vote back."
Lang said a key part of the suit is the restriction requiring that all fines and fees be paid, which the suit says disproportionately affects minority voters.
"Striking down that provision would allow far more people to restore their right to vote," she said.
The moral turpitude standard, which the suit claims is intentionally racially discriminatory, first appeared in Alabama's 1901 Constitution when it was more broadly applied to all crimes.
Lang said the phrase was written into to the 1901 constitution "partially because it is discretionary and arbitrary, so it allowed legislators and elected officials to weed out black voters and allow white voters to continue to vote."
The Supreme Court struck the phrase from state law in 1985, saying it violated the Equal Protection Clause.
But it reappeared in 1996, when legislators added it to the state's felony disenfranchisement law.
A vague standard like "moral turpitude" still makes it easier to purge black voters from voting lists today, said Lang.