It's going to be hard to argue with people on the basis of what was "good". That's subjective, and the very basis for why there are separate parties.
I'd expand this to examples of either party undoing legislation the other championed and passed. It's exceedingly rare, in large part by design.
The reason Republicans are mentioned above is that they have a well documented public history of endorsing and carrying out these kinds of shenanigans. Democrats, though cut from the same cloth, somehow manage to be one step above on an imaginary decency scale.
We didn't even allow the 2001 Bush tax cuts to automatically expire at the end of 2010, despite control of the House, Senate, and White House passing from the Republicans to the Democrats during the intervening years.
Since the Republicans lacked 60 votes in the Senate and zero Democrats supported the Bush tax cuts, The law enacting them was passed using budget reconciliation rules.
> Budget reconciliation is a special parliamentary procedure of the United States Congress set up to expedite the passage of certain federal budget legislation in the Senate. The procedure overrides the Senate's filibuster rules, which may otherwise require a 60-vote supermajority for passage. Bills described as reconciliation bills can pass the Senate by a simple majority of 51 votes or 50 votes plus the vice president's as the tie-breaker
https://www.wikipedia.org/wiki/Reconciliation_(United_States...
Using budget reconciliation rules automatically set a sunset date for the tax cuts, after which they would automatically expire.
When the tax cuts should have automatically expired at the end of 2010, the Democrats controlled the House, Senate and White House. Despite frequent claims over the decade that tax cuts for the rich were morally reprehensible, the Democrats did not allow the tax cuts to automatically expire, extending them for two years in the lame duck session of Congress, and then most were made permanent two years later before they should have expired again.
Isn't that the opposite of "undoing legislation"?
The main change at the border is a larger number of migrants. Migration trends are up globally, for a variety of reasons including climate change.