That in 1968, the NRA supported gun control; that in 1972 the GOP platform supported gun control, but in ‘76, opposed it based on a Ronald Reagan taking a different position that President Gerald Ford. From Jeffrey Toobin’s “The Oath:”

Reagan worked opposition to gun control into a broader libertarian message. To him, gun control was just another big-government program that did more harm than good. Gun control punished law-abiding citizens while leaving firearms in the hands of criminals. What was more, Reagan hinted, gun control was prohibited by the Second Amendment. “The Second Amendment gives the individual citizen a means of protection against the despotism of the state. The rights of the individual are preeminent,” Reagan wrote in Guns & Ammo magazine in 1975. “The Seconed Amendment is clear, or ought to be. It appears to leave little if any leeway for the gun control advocate.” (page 102)

The political and legal branches of the conservative movement joined forces in support of a new reading of the Second Amendment. On May 21, 1977, a hard-line faction of the National Rifle Association staged a coup d’etat at the annual meeting of the group, in Cincinnati. Out went the traditional emphasis on gun safety and in came a new focus on political action, especially in fighting gun control. (Page 103).

Nevertheless, gun rights joined “family values” and the anti-abortion fight as key planks of the conservative agenda that in 1980 propelled Reagan into the presidency and the Republicans into the Senate majority. (page 103)