Virginia Attorney General Mark R. Herring's decision Thursday to stop defending the state’s ban on same-sex marriage is the latest reminder that down-ballot races, while less sexy than contests for governor or Senate, have lasting political and policy consequences.

Herring, who won the AG's race last fall by less than 1,000 votes, announced Thursday that he would join two same-sex couples in asking a federal court to strike down Virginia's gay-marriage prohibition on the grounds that it was unconstitutional. In doing so, he joins a growing list of Democratic office holders who have opted out of defending same-sex marriage bans.

Pennsylvania's AG Kathleen Kane made headlines in July when she refused to represent the state in a lawsuit on the issue; in Hawaii, Gov. Neil Abercrombie (D) filed court papers last year calling that state’s gay marriage ban unconstitutional. In Illinois, Democratic officials including state Attorney General Lisa Madigan have declined to oppose a lawsuit filed in 2012 seeking same-sex licenses from the Cook County clerk.

And while Democrats have generated plenty of news when it comes to gay rights, Republicans have also made a point of refusing to argue in court for laws they consider unconstitutional. Indiana Attorney General Greg Zoeller (R) declined to defend a portion of that state’s immigration law after the Supreme Court struck down a similar provision in Arizona's immigration law. Herring's predecessor, Attorney General Ken Cuccinelli II, decided last year he would not defend one of Gov. Robert F. McDonnell’s key education reforms on the grounds that he believed legislation allowing the state to take over failing schools did not pass constitutional muster.

The very fact that Herring was in the position to change the state's stand on the same-sex marriage lawsuit, to some extent, reflects the reason that advocates have become more sophisticated about engaging in races like his.

When the campaigns were calling all provisional ballot voters in Fairfax County after the November 2013 and urging them to come to the county offices to show identification to prove their provisional ballot should be counted, according to the Human Rights Campaign's field director Marty Rouse, one voter showed up and was told his provisional ballot would be denied.  Soon thereafter, the Herring campaign challenged the denial and won, but it needed the voter to come in a second time to have the ballot counted.

Herring personally called the voter in question and urged him to return so his vote would be counted. According to Herring, who recounted the story to Rouse, the supporter told him, “I am gay, and I got an e-mail from the Human Rights Campaign urging me to vote for you. I want you to win to protect not only my rights, but everyone’s rights. I’ll be there in a few minutes.”

What does this mean going forward? Groups on both sides of key domestic policy fights -- including gay marriage, abortion and immigration -- are likely to target attorney general races in Colorado, Ohio, Michigan, Illinois, New Mexico and Nevada this year. If they needed any more incentive to get off the fence and become more involved in these campaigns, Herring just gave it to them.