Richard Hasen is the nation’s leading scholar on elections law as political weapons and constitutional fights. A University of California-Irvine political scientist and law professor, Hasen was in Raleigh last week speaking at N.C. State University. His topic: “Race, Party and Politics: North Carolin’s New Front in the Voting Wars.”

Naturally, I thought of our Attorney General Roy Cooper, who wants to be governor. Cooper has a constitutional problem. I’ll get to it shortly.

But first, as Hasen did, consider the case of a political party thatunder the guise of “reform”passes election laws designed to cripple the rival party by disenfranchising African-American voters.

North Carolina, 2013?

Not yet: Hasen started with North Carolina in 1898, when the all-white Democratic Party ousted the fusionist Republicans (blacks and some whites) who’d governed after the Civil War. “Reforms” then prevented most blacks from voting, and the Republican Party ceased to be a force.

In 2013, the parties have flipped, but the situation is familiar. The Republican Party, virtually all-white, is in charge. This year’s Republican “reforms”the infamous House Bill 589, which critics term a voter-suppression law and which, Hasen said, is the most restrictive set of voting requirements passed by any state since the civil rights erawill hurt the Democrats, now the party supported by almost every African-American voter.

So, Hasen asked: Was 1898 about race? Or party? And is 2013 about party? Or race?

Unless you’re a constitutional lawyer, he said, the answer in each case is both. Because in America you can’t disentangle race and politics.

But in the realm of constitutional law, he noted unhappily, the U.S. Supreme Court insists that it can disentangle the two. And while intentional racial discrimination is unconstitutional, political discrimination is permissible even if it has the incidental (wink, wink) effect of hurting African-Americans.

Last month, the U.S. Department of Justice filed suit in federal court against the state of North Carolina and Republican Gov. Pat McCrory, charging that HB 589 is intended to discriminate against African-American voters and therefore violates the federal Voting Rights Act of 1965 and the 14th Amendment.

The state’s position: No racial discrimination was intended.

Cooper, a Democrat, urged McCrory to veto HB 589. Nonetheless, he’s announced that he will defend the law in court. This means one of two things: Either Cooper thinks the DOJ is wrong and the law is constitutional, or he thinks he has a duty to defend an unconstitutional law. Either way, he’s making a mistake.

Uninhibited by a law degree, it’s apparent to me that the Republican Party in North Carolina is not merely uninterested in whether it’s discriminating against black voters, it’s actively seeking to be the party for white voters with racist resentments.

Just in the last week, we’ve had two examples of this Republican mentality. One was Don Yelton, a Buncombe County GOP precinct leader who proclaimed on The Daily Show that the Republican election law will “kick Democrats in the butt.” Further, Yelton said, “If it hurts a bunch of lazy blacks that want the government to give them everything, so be it.”

Then state Rep. Larry Pittman, a Concord Republican, told a snickering audience that President Obama is not a traitor “as far as I can tell.” Said Pittman: “I haven’t come across any evidence that he has done one thing to harm Kenya.”

Now look at HB 589. It’s a 50-page compilation of every pernicious idea passed by a Republican legislature anywhere for the purpose of suppressing voter participation. Plus it invents some new ones, such as requiring a photo ID at the polls but not accepting an official student ID.

HB 589 doesn’t inconvenience only African- Americans voters. But past elections demonstrate, the DOJ lawsuit says, that African-Americans were the most likely to use early voting and same-day registration, to cast provisional ballots (because they’re registered in one precinct but moved to another) and to lack a current driver’s license with photo ID.

And, sure enough, the lawsuit charges, HB 589 cuts a week off early voting, ends same-day registration, disallows most provisional ballots, and its photo ID requirement “lacks the types of protections for voters without identification that are common in other states that require” an ID.

Let’s underscore the point: North Carolina, like the rest of the South, has a history of government by all-white political parties, which is why the 14th Amendment was neededand the Voting Rights Actto prohibit the states from passing laws intended to cement the white party in power.

The question before the federal court is whether HB 589 is such a law. We can’t look into Republican hearts. But we can infer their intentions from one fact, which Hasen and others have spotted: There is no sensible reason for the law except voter suppression.

So now, what should Cooper do? State law directs the attorney general to “appear for the State … in any cause or matter, civil or criminal” in which North Carolina is a party.

But the attorney general is elected as an independent constitutional officer, and his job isn’t to defend any law regardless of its constitutionality. It’s to represent, yes, the Statemeaning the people of North Carolina. And his highest duty is to defend the Constitution of the United States.

Cooper, when he wrote to McCrory urging a veto, said he was offering “public policy objections and not legal opinions.”

Since then, Cooper’s been campaigning as an all-but-announced candidate for governor in the 2016 Democratic primary. Does he really think he can straddle the fence for three years on this critical issue? Defend voter suppression as constitutional but criticize it on the stump?

Ironically, McCrory gave Cooper an out by hiring his own counsel. Cooper should go into court and declare that, in his legal opinion, HB 589 violates the U.S. Constitution and must be struck down. Not because it’s good politics. Because it’s his duty.

This article appeared in print with the headline “Flex that legal muscle.”