The state recently passed the most restrictive abortion ban in the country, and advocates are now challenging a slate of other laws and regulations restricting the procedure.
The measure, which is poised to become law once signed by the governor, allows for exceptions only in a "medical emergency and in cases of severe fetal abnormality."
"I regret my health has become an ongoing challenge," the 80-year-old Republican said Monday. His decision sets up a nonpartisan special election to coincide with the November general election.
Mississippi state Sen. Chris McDaniel, who nearly upset Sen. Thad Cochran in a bitter 2014 race, is teasing that he will mount a conservative primary challenge to Republican Sen. Roger Wicker.
Two black Democratic lawmakers who decided not to attend said Trump's presence at the opening was "an insult." But the state's GOP governor said residents should be proud Trump would be there.
Organizers hope to stay focused on the museum's message for its opening, despite African-American congressmen's objections to President Trump's presence.
Forecasters expect lower temperatures and some precipitation with a storm front moving across the Southeast. Though most estimates top out at 2 inches of snow, ice isn't out of the question.