The red line is when Republicans ended the national assault weapons ban.

Source:
https://www.channel4.com/news/factcheck/factcheck-does-gun-control-work
Also, https://www.instagram.com/p/CeEZJNJu5X2/
Note: In 2004 the Republican Congress refused to renew the assault weapons ban

FactCheck: does gun control work?

States with stricter gun laws have lower firearms deaths - but is one causing the other?

Channel 4 News
@AthenasOwl I honestly believe they undid the ban just to watch people die
@gavinisdie That would be bad, but the reality is worse: They just didn't care. They did it for political reasons, to win support from meatheads who love guns. The consequences weren't important to them.