What does that mean? All Presidents are responsible for their actions and for the actions of those under them when operating under his orders.
So yes; all by himself. I liked Reagan for the most part but his amnesty thing was the worst thing this country has seen immigration wise. He should have known the left had no intention of keeping their word about securing the border. If he didn't it would mean he was naive and incompetent and I don't buy it. He knew. It was far worse than just giving those people free citizenship after so many had to work and wait for years and years to get it; it put a big ole welcome sign to illegals going forward on every border.
I'm so glad we have a President, an AG, a DHS secretary now who have the spine to enforce our border laws and start punishing those who break them in a serious way. Making it a felony for anyone who has been caught and deported to again be in the USA illegally should have been done 60 years ago. At least it's happening now.
And they are DOING it in accordance with the LAW.
NONE are doing it 'by themselves'.