Virginia Attorney General Mark Herring says he merely followed precedent. The rookie attorney general generated a storm of controversy by switching sides in the federal lawsuit challenging Virginia’s constitutional ban on same-sex marriages and civil unions. Republicans claimed Herring flouted his oath of office, leading some to draft articles of impeachment. One lawmaker vows to file a complaint with the Virginia Bar.

A new constitutional crisis? Rather the oldest issue in politics.

Herring’s office filed a “Notice of Change In Legal Position” in the case of Bostic v. Rainey.  Defendant Janet M. Rainey is the state registrar of vital statistics. State law obligates the attorney general to defend her, along with the challenged state law or constitutional provision, except in limited circumstances.

During the 2013 campaign, Herring supporters knew that key swing voters questioned if he would defend the marriage ban. In justifying their endorsement, the Virginian Pilot wrote: “[Herring] has reversed his position on gay marriage, favoring repeal of the constitutional amendment that he supported in 2006. … He has noted that his job, if he is elected, would require him to try in good faith to find a basis to defend the amendment’s legality, a duty that he has pledged to fulfill.” (Emphasis added.)

But once safely elected, Herring said he could find no such “good-faith” defense. He didn’t know this two months ago? Former Virginia Attorney General Ken Cuccinelli told us he used the same “good faith” standard when he decided to defend the ban. Many scholars, and the only Supreme Court decision that’s directly on point, suggest this marriage issue is reserved for state law.

In 2006, then-Sen. Herring apparently saw a good-faith basis to believe the ban passed constitutional muster, given that he supported the amendment. But Attorney General Herring now cannot find any good-faith defense at all? In 2012, President Obama declared support for same-sex marriage. But he said that states possessed a federal constitutional right to define marriage under state law. Obama’s fellow Harvard Law graduates Mark Warner and Tim Kaine, along with Gov. Terry McAuliffe, likewise backed Virginia’s ban until recently. Herring surely concedes that these Democratic leaders wouldn’t have taken such position without a good-faith constitutional belief.

With all due respect, there is only one good-faith conclusion to be drawn here: Herring chose not to live up to his pledge to Virginians.

Herring excuses this failure by claiming his constitutional reasoning is beyond good-faith dispute. We disagree, as does the respected It points out Mr. Herring’s legal position in fact “goes further than the Obama administration has gone, and than any federal appeals court has gone.”

This doesn’t mean the AG is wrong. A recent 9th Circuit U.S. Court of Appeals decision is the latest example of a court seemingly expanding constitutional protections for same-sex marriage. But Virginia is in the 4th Circuit, and lawyers are taught to read decisions narrowly.

Did Herring violate the “Rules of Professional Conduct” sanctioned by the Virginia State Bar to regulate ethical attorney behavior? His office failed to adequately explain procedural and other ramifications attending his legal switch, but we fail to see the justification for a bar complaint. 

Bottom line: Mr. Herring made a calculated political decision. In political shorthand, the electoral energy behind “gay rights” today eclipses “civil rights,” perhaps even “women’s rights,” in the Democratic Party. Lt. Gov. Ralph Northam had best take note for 2017.

No law prevents a politician from breaking his promise. But having the right to do it doesn’t make it the right thing to do.

Norman Leahy is an editor of the conservative Web site and producer of the political radio show “The Score.” Paul Goldman is a former chairman of the Democratic Party of Virginia. They are blogging together on All Opinions Are Local during Virginia’s 2014 General Assembly session.