Lately, Republicans leaving their party to become a Democrat is rare. When it happens in the South, it’s even rarer. When it happens in in Mississippi, it’s practically unheard of.

And when it happens because of “Obamacare,” one can hardly believe their eyes. But my colleague Laura Conaway flagged this piece from the Clarion Ledger this week, and the story is absolutely real.

Former Republican state Sen. Tim Johnson on Wednesday announced he’s switching parties and challenging incumbent Republican Lt. Gov. Tate Reeves this year. But the noted Elvis impersonator said he won’t be appearing as the King on the campaign trail.

According to the local report, Johnson held a press conference at the state Capitol and reportedly told supporters, “Why join the Democratic Party and run for lieutenant governor? I’ll tell you: We are all Mississippians first. Elected officials should be in the business of helping all Mississippians, not picking out who to hurt.

“The Republican Party leaders’ actions against supporting Medicaid expansion and threatening our local hospitals was the final, deciding factor for me.”

I was tempted to compare this to a blue moon, but c’mon – blue moons are practically common compared to stories like these.

Keep in mind, Mississippi isn’t exactly a competitive battleground for Democrats. The governor’s office and state legislature are controlled by conservative Republicans, and most statewide offices are held by the GOP. There have been a large number of party-switchers over the last couple of decades in Mississippi, but they’ve all moved away from the Dems, not towards the Dems.

The Affordable Care Act, meanwhile, probably isn’t the most popular idea in the Magnolia State.

And yet, here we have a former two-term state senator not only walking away from Republicans, but doing so in part because his party won’t embrace Medicaid expansion through the ACA.

According to the Clarion Ledger, state Democratic Party Chairman Rickey Cole, not surprisingly, welcomed Johnson. Cole added that he believes the GOP has “turned a lot of people off” with “extremist politics.”