Just when I thought this thread jumped the bear, someone writes something substantive...
It's called an arms race, and competition brings out the best in people.
The Heller decision is not even 15 years old. In the United States, it's extremely difficult to amend the Constitution, which justifies a loose interpretation. Conservatives have for decades been pushing the idea that the Second Amendment somehow justifies individual private gun ownership for self-defense. They've been pushing a living Constitution interpretation but called it "Originalism." The Court resurrected the First Amendment in the 20th century, and the Second Amendment in the 21st century.
A concerted effort the other way could see Heller overturned (just as conservatives overturned pro-gun control decisions, and will probably soon overturn abortion rights). Another flip on guns might seem unlikely, but it's more likely than securing a two-thirds vote in Congress and three-quarters of the state legislatures. The difference is that a newly constructed High Court will, even theoretically, take a long time, whereas a repeal could theoretically happen within months. Nevertheless, the former is much more realistic than the latter. It's just going to take a lot of time, and many people will needlessly die.