The uproar over a militant occupation of a federal outpost in Oregon began with a rather mundane dispute over the criminal prosecutions of Dwight and Steven Hammond, a father and son who waged a byzantine fight with the federal government and lost.

Neither man even took part in the anti-government protest that began over the weekend. Yet the length of their prison sentences is somehow at the center of it.

A closer look at the Hammonds' legal spat reveals there really isn't much to it. Although there's a larger debate over the wisdom of any and all mandatory minimum sentences (see more below), the five-year term that each man was ordered to serve is perfectly legal.

The two ranchers reported to federal prison on Monday, and no haphazard insurgency will get them out.

Federal and local authorities are responding in kind: They don't seem very impressed by the occupation so far.

Which isn't to say there isn't something legitimate about the occupiers' grievances as they speak to the broader ills of the American system of punishment.

Rick Bowmer/Associated Press Armed protesters took over the Malheur National Wildlife Refuge on Saturday after a peaceful rally over the prison sentences of local ranchers Dwight and Steven Hammond.

The Hammonds' troubles began in June 2012, when a jury convicted them of "maliciously" setting fire to large swaths of federal land in 2001 and 2006 -- a federal crime carrying a mandatory minimum penalty of five years in prison.

The U.S. Court of Appeals for the 9th Circuit, which reviewed the Hammonds' sentences in 2014, explained that the jurors relied in part on testimony that during the 2001 fire, Steven Hammond told a teenaged relative to drop lit matches on the ground so as to "light up the whole country on fire." The blaze consumed 139 acres of public land, and apparently endangered the teen.

The case would have been over had the trial court imposed the five years of imprisonment that the law mandates. Instead, the judge cited the Eighth Amendment -- which bars "cruel and unusual punishment" -- and second-guessed Congress, concluding that the mandatory sentence was "grossly disproportionate" to the offense. He proceeded to sentence Dwight Hammond to three months and his son to a year and one day in prison.

Federal prosecutors appealed, arguing what they often argue when mandatory minimum sentences are at stake: that the law is the law and that judges have no discretion to deviate from it.

The 9th Circuit agreed and essentially ruled the Hammonds' lesser sentences to be illegal.

"Given the seriousness of arson, a five-year sentence is not grossly disproportionate to the offense," the appeals court said, before offering a lengthy list of "far tougher sentences" that the Supreme Court has upheld for arguably less-serious crimes, like stealing golf clubs and possessing small amounts of marijuana.

Justin Sullivan/Getty Images Ammon Bundy, a leader of the anti-government militants that took over the wildlife refuge center, staged the occupation in support of the Hammonds.

The Hammonds, in turn, looked to the Supreme Court. In March of last year, the high court declined to hear their appeal. By then, the men had already served their shorter sentences and were under supervised release.

Without any recourse left, the two ranchers had to accept their fate: five years behind bars, minus any time they had already served. Or as the 9th Circuit wrote when it threw out the original punishment, they had to be resentenced "in compliance with the law."

That happened in October, and the Hammonds surrendered themselves on Monday as they were directed, bringing their personal battle with the federal government to an end.

It is not wholly irrational, in view of all this tussling, to sympathize with the Hammonds and maybe even with their supporters, some of whom view the sentencing controversy as symptomatic of government overreach. But in the grand scheme of efforts to reform mandatory minimums, their case is only one of thousands -- and many end up with longer sentences.

The Hammonds' case is "fairly run-of-the-mill," said Ohio State law professor Douglas Berman, a sentencing expert. "The ugliness you identify here is an ugliness in the way our federal justice system operates."

The ugliness you identify here is an ugliness in the way our federal justice system operates. Professor Douglas Berman

What Berman means is that federal prosecutors often seize on language in a statute -- here, malicious destruction by fire of property belonging to the United States -- and apply it to seemingly petty examples of such conduct. Later, they seek the stiffest punishment allowed, no matter how unfair the end result. And if the law calls for a mandatory minimum, the work is pretty much done for them.

"I do think Congress did not have in mind the Hammonds for these mandatory minimums," Berman said, adding that "prosecutors can always convince themselves" that a particular misdeed is really serious and therefore a harsh penalty is what legislators intended all along.

Here's where the broader debate over mandatory minimum sentences goes -- and why any fury over what happened to the Hammonds and others like them should be aimed at Congress, which writes the laws that tie judges' hands and forbid them from showing leniency.

"The Hammonds join ... countless other individuals who were denied the opportunity for a judge to exercise appropriate judgment in imposing a rational sentence," said Rep. Bobby Scott (D-Va.), a staunch opponent of mandatory minimums, in a statement on Tuesday. Scott has sponsored or co-sponsored a number of bills aimed at curtailing the practice. If decades of unduly punitive sentencing policies have shown us anything, it is that thousands of people like the Hammonds -- ordinary Americans who may have broken the law, but are far from hardened criminals -- bear the brunt of Congress' folly.

"They're comparable to a heck of a lot of people -- especially black and brown people stuck with mandatory minimums," Berman said.