What we haven’t seen this year, however, is a sitting governor face a criminal indictment. That changed late yesterday afternoon.

Texas Governor Rick Perry was indicted Friday by a grand jury on abuse of power charges stemming from his battle to defund a state-funded bureau of anti-corruption investigators. […] Special prosecutor Michael McCrum told NBC News affiliate KXAN that Perry faces two counts of abuse of power. “The grand jury’s spoken that at least there’s probably cause to believe that he committed two crimes, two felony crimes. For count one its 5-99 years in prison and for count two its 2-10 years in prison,” said McCrum.

In a written statement, the Republican governor said he was “outraged and appalled” by the indictment, which he considers “political abuse of the court system.”

If this seems to have come largely out of the blue, it’s not your imagination. While some gubernatorial scandals, such as Chris Christie’s troubles, have become high-profile controversies that unfold over the course of months, Perry’s story has been generally overlooked. In fact, even in Texas, it was widely assumed that the investigation wouldn’t amount to much.

Those assumptions, it turns out, were wrong. So, what’s this case all about?

The story starts, oddly enough, with a DUI. In April 2013, Travis County District Attorney Rosemary Lehmberg was arrested for drunk driving. She eventually pleaded guilty, apologized, and served 20 days behind bars for her first offense.

But Lehmberg, who’d been easily elected to her D.A. position, did not resign her post. That didn’t sit well with Rick Perry, who said she should resign in light of the DUI incident. Lehmberg refused.

So, the governor decided to kick things up a notch. Perry announced that if Lehmberg did not resign, he would use his veto power to strip her office of its state funding. When Lehmberg ignored the threat, the governor followed through and vetoed the funding.

At this point, some might be wondering what the big deal is. After all, it hardly seems outrageous to think a governor would want to see a district attorney step down after she spent a few weeks in jail. If the law authorizes Perry to use his veto power, how could it be illegal?

According to the prosecutors who secured the indictment, the answer is: context is everything.

In this case, Rosemary Lehmberg wasn’t just a D.A. who got caught drunk driving. She’s also a Democrat. What’s more, she’s the district attorney for Travis County – home to Texas’ state capital – which gives Lehmberg responsibility for investigating allegations against leading officials in state government, including all ethics complaints against Texas state officials through a Public Integrity Unit that Lehmberg helps lead.

And given that this is Texas, where Republicans dominate, the fact that there’s a Democrat in charge of a Public Integrity Unit that investigates GOP officials doesn’t sit well. Republicans have long wanted one of their own in that office. (Note, it was the Travis County D.A.’s office that indicted then-House Majority Leader Tom DeLay nearly a decade ago.)

Given these details, the innocuous explanation is that Perry used his legal authority to push out a district attorney who got caught committing a crime. The not-at-all-innocuous explanation is that Perry used the DUI as a pretense to gut a Public Integrity Unit so that Republican state officials would face less scrutiny from a pesky Democrat.

The grand jury appears to have concluded that the latter explanation has merit.

But if the governor has veto power under the state constitution, how can his reasoning be legally problematic? That’s no doubt what the defense attorneys will say, but as Rachel noted on the show last night, “You may have the constitutional right to vote, for example, you don’t have the constitutional right to sell your vote. Your action itself is not necessarily independently evaluated from its motives in a case like this.”

Perry will be arraigned next week. How this might affect the governor’s presidential ambitions – he’s been spending quite a bit of time in Iowa lately – remains to be seen.

[ Note to readers : our usual Saturday feature, “This Week in God,” is off today, but it will return next week.]