So why didn't he do this 8 years ago?

[Hekate]

15. Congress passes laws. Executive Orders are good only for the term of office of the President...

I think setting up National Parks is the exception to the rule.

President Obama's legacy regarding urgent business he could not get past this GOP-infested Congress is going to be fragile. If the next president is a Democrat, they will let his EOs stand. If the next president is a Republican, well when you hear them on the campaign trail bloviating that they will overturn this or that item on their first day in office, they really can do that with Executive Orders.

The whole reason Obama tried so hard and so long to get Congress to do its damn job is that THEY MAKE THE LAWS. Laws which cannot be overturned by the whim of the next person who becomes president.

If you want a good example of this, google for "Global Gag Order." I'm personally well-acquainted with this one because I am a lifelong supporter of women's health care and Planned Parenthood. This particular issue has been a political football since probably the Reagan years. Republican presidents reinstate in on their first day in office. Democratic presidents banish it on their first day in office. Neither can get it through Congress, so the show goes on. The only people who suffer are women overseas who get pregnant from rape and cannot even be told where to go to get help ("gag order"}. Who cares if their village stones them to death, right? Just look it up.