Rand Paul’s opposition to abortion may not be enough to convince certain social conservatives that he warrants their support.

Not even a week after the Kentucky senator and early frontrunner for the Republican presidential nomination took to the stage at the Family Research Council-hosted Values Voter Summit, he has found himself at war with the group’s president over his contention that Plan B is birth control—not the abortion-inducing drug that some have made it out to be.

While campaigning in South Carolina on Tuesday, Paul was asked if Plan B should be legal. He replied: “I am not opposed to birth control… Plan B is taking two birth-control pills in the morning and two in the evening, and I am not opposed to that.” Paul later reiterated that position to reporters, stating: “Plan B is taking birth control… I am not against birth control, and I don’t know many Republicans who would be indicating that they are against birth control.”

This evidently set off Tony Perkins, president of the Family Research Council, who on Thursday afternoon took to Twitter to needle Paul:

Paul’s camp, according to a senior adviser, is “fuming” at Perkins’ criticism, “especially when he heard Rand talk about his commitment to life at his conference, and saw the video compilation of his other pro-life speeches.”

Perkins didn’t reach out to Paul or his staff before making the remarks, according to the adviser. “He reaches out when he needs a speaker for his conferences, but apparently not when he wants to attack Sen. Paul for no good reason.”

Paul’s speech at the summit last Friday may not have been the sermon delivered by Sen. Ted Cruz, but it was sincere. Paul has historically opposed abortion—even in cases of rape and incest (his only exception being when the life of the mother is at risk). “I believe that no civilization can long endure that does not respect life from those not yet born to life’s last breath,” he told the crowd. “I am one who will march for life and will continue to stand up in defense of life as long as I am privileged to be in office.”

Not exactly a vague endorsement of that important part of the social-conservative doctrine—but perhaps not enough for people like Perkins, much to the ire of Team Paul.

“One million unborn children are aborted each year in the United States, and instead of doing more to end that, self-styled pro-life leader Tony Perkins is picking a ridiculous fight over contraception with a pro-life senator,” the Paul adviser told The Daily Beast.

“Plan B is completely different than abortion pills like RU486—which Rand opposes. Mr. Perkins’ intransigence over whether or not to ban birth control is unfortunate and detrimental to the cause he seeks to champion.” Paul “will continue to lead the fight for unborn children, but won’t be given medical advice by Mr. Perkins or anyone else in Washington.”

There are probably worse people for Paul to have as an enemy than the plastic-grinned Perkins, who has spoken to white-supremacist groups and expressed a number of eyebrow-raising beliefs. Just this week, Perkins claimed that the success of the LGBT movement could have “deadly consequences” for people like himself who are definitely not gay at all. He didn’t say exactly what could be deadly, but one assumes Perkins fears being accidentally stomped to death at a pride parade the way some people fear clowns.