Quite honestly, if there is another large-scale massacre the next time the democrats control congress and the White House, or are close to controlling Congress, there’s a damned good chance the Second Amendment will be repealed in its entirety.
When that’s gone, all bets are off.
The 2A is not going to be repealed - it doesn't have to be. Instead, it will be effectively neutered by a SCOTUS decision.
What the Supreme Court granted in Heller it can take away. Just as pro-lifers have agitated for years for the SCOTUS to reverse its finding of rights for women, so are liberals salivating for the day when the Supreme Court can reverse Heller and render the 2A an anachronism.
Even with Heller still on the books, there's little question that a good-faith regime of gun registration, licensure and insurance is Constitutional as a reasonable regulation of the gun right. And most gun owners will understand and comply, just as drivers understand why motor vehicles need to be registered and insured.
And following nearly a century of automobile registration, there's still no evidence it leads to confiscation!