It looks more like a "Cuban Missile Crisis" stand-off to me than a "Bay of Pigs Invasion" (let alone the Normandy Landings). There were limits to what a hastily assembled federal force could have done with the free White population of South Carolina in arms against them, so I'm thinking Lincoln was just trying to be prepared for different contingencies, rather than planning some kind of invasion.
You need to read the messages PeaRidge has posted regarding the outfitting of those ships, the manner in which they were outfitted, the manner in which the orders were given, and their behavior up to, during, and subsequent to Ft. Sumter.
It very much looks as if Lincoln very deliberately launched an invasion, and I expect he would have gotten away with it as well, so far as the Northeaster media would have reported it.
Just as then, same as now, the media were in the pockets of big government Liberals. Lincoln was a Liberal for his time period. The Social Justice Warriors of that time period were Northeaster Liberals (Harriet Beecher Stowe) from big cities like New York and Boston, and a divisive Lawyer from Illinois was running the country.
There are a lot of modern parallels with the past.