SCOTUS also ruled that the above has to go thru the congressional way with regard to the EPA ruling.  What Chev Diff (CD) is, it was a way of passing rules decades ago that the EPA used against oil companies. Instead of making bills and voted on by Congress, then into law, the EPA was allowed to change the rules on things and bypassing this process.

Then the AFT caught on and began doing the same.  They can change the definition of things, like what is a machine gun, or what is a firearm (80%) making people felons for having items that once were not classified as such.

This is HUGE

This has a big effect on the Feds overall, to include the ATF, lead to smaller and more stable Federal government now that we don't have to worry about rules changing with every administration.