GOP state Rep. David FitzSimmons became more than a conservative newbie last May when he secured passage of an amendment giving churches that refuse to perform same-sex marriages sturdier legal protection, and then voted for the marriage-legalization bill. He became a good legislator.

FitzSimmons, a 35-year-old agricultural project manager, also became a political whipping boy for the social conservatives who control the dominant Republican Party in his Wright County district. Since May, he’s been the target of vitriol, untruths and threats severe enough to be turned over to law enforcement.

At last Saturday’s District 30B GOP convention, he became a lame duck. FitzSimmons announced before the balloting that he would not seek a second term in the face of Dayton City Council member Eric Lucero’s endorsement challenge, which focused almost exclusively on the marriage vote. Lucero then won the party’s nod for the seat.

As a result, a promising legislative career has been cut short — but that’s not what’s most lamentable about FitzSimmons’ impending departure from elective office. What’s worse is that his fate will become a cautionary tale, both discouraging similarly able people from running for the Legislature and deterring sitting legislators from seeking middle ground in the midst of controversy.

The FitzSimmons story also will reinforce claims that the state Republican Party is an association of social-issue purists, intolerant of deviation. That reputation is easily overstated by GOP critics. It’s noteworthy that on the same Saturday, another GOP legislator who voted for the marriage bill as amended by FitzSimmons — Patrick Garofalo of Farmington — won easy endorsement for a sixth term.

But the developments in District 30B likely will be remembered longer, and won’t help state GOP leaders’ efforts to widen their party’s reach. Neither will it help state government become more functional. The perceived price of compromise just went up.

FitzSimmons possesses strong Republican credentials. He was the manager of GOP gubernatorial candidate Tom Emmer’s 2010 campaign and a top adviser to 2012 Republican Senate candidate Kurt Bills. As a legislator, he chalked up a 100 percent rating on the annual scorecard of the GOP-allied Taxpayers League of Minnesota. Last fall — as he was being vilified for accepting “gay money” for his campaign — he turned all of his 2013 donations over to joint Republican efforts to return control of the state House to the GOP.

He has no regrets, he said Monday. “I knew this possibly was going to be a vote that would put me out of office,” he said of the vote for the same-sex marriage bill, as amended. “But I would do it again. I made the best long-term decision I could for my constituents. If you don’t try to do what’s best for your constituents, it’s not worth being in office, anyway.”

Courage and a focus on one’s constituents are hallmarks of a good legislator. It will be a shame if FitzSimmons’ fate at his own party’s hands results in Minnesota having fewer of them.

— Minneapolis Star Tribune, Feb. 24