Or the populace lurches in the other direction and becomes hardened against the attackers and starts electing governments that vow to get 'tough' on the terrorists...
...More realistically there would be a tension between 'Just give them what they want so they leave us alone' and 'find the bastards who dared attack us and deal with them'. Which way that tension gets resolved ultimately might depend on a whole host of factors, starting with the politicians that are the most able rally people to their causes.
That there would be. Successful Insurgencies are pretty much all about PR management, and brutal tactics.
If it gets nasty in Cuba, which by all means it probably will, (same as what happened in the Dominican Republic at the time or Vietnam in a few years,) that's going to get on the news stateside, in a very big way. You'll have Journalists like Walter Cronkite and Dan Rather covering all of it, and they're not going to be too fond of US actions in Cuba. This, combined with a steady stream of Casualties over say five to twelve years, and the odd high-profile attack in the states, means you'll likely get the same sort of response in the States as the Algerians got out of the French, and public perception of the war would likely be similar to Vietnam after the Tet Offensive.
Did I do something to a beloved pet of yours to make you so hostile?
No, you just have this inherent ability to piss me off.
This could just as easily turn straight around and become that patriotic rallying point where Americans are chanting "Remember X", X being whatever building or gathering that got bombed to smithereens by Cuban guerrillas. The psychology of fear is an awfully finicky thing. It's unpredictable really, you can just as easily disillusion people into wanting an end to the bloodshed, but you can also merely set the resolve of the public to see the war through to its end.
That resolve
never develops when you're playing whack-a-mole with insurgents. Look at the Philippine War, Algeria, Kenya, the Portugese Colonial Wars, Vietnam, Afghanistan, Iraq, and the list goes on. And as soon as the media turns against the war, the nation will too.
The best aid the Soviet union could provide to the reborn M-26-J in such a case is setting up a front group, and financing a PR campaign in the US and Western Europe.
Ah yes, that narrative -- rejecting, out of hand, the possibility of US alliance with anti-communist socialists, reformers, and democrats, because "the US has, throughout its entire history, always ever only looked to promote the bottom line of her corporate clients". Never mind the times that the US did buck massive economic interests to build good relations with third-world nations (eg the Suez Crisis) never mind that the US has allied with nations enforcing land reform; never mind that the US cut off Batista and worked to accelarate his downfall with embargoes and CIA aid to the revolutionaries; never mind...
Yeah, except pretty much everyone you listed got lumped together under the Label communist sympathizers in Latin America, and got shot for it, unless they were little old ladies.
But the problem really is you're conflating US policy in the rest of the world with US Policy in the Caribbean and later on Latin America as a whole. It's the politics of empire, admittedly normally more subtle than traditionally practiced, but on occasion the gloves did come off, and the CIA would find someone to do their dirty work for them. Batista isn't reliable? Work to oust him. The new guy isn't so hot either? Kill him.
(breathes deep) Look, I'm not saying the US never recklessly acted for the benefit of big business, at the expense of losing hearts and minds to communism -- but it wasn't a natural result of anything, but a factor competing with sane anti-communist US policy.
There was no such thing as sane anti-communist policy back then. US Policy at the time led to witch hunts at home and in Latin America, backing the Junta in Greece, everything associated with Operation Gladio in Europe, and backing South Vietnam instead of trying our damnedest to lever the North out of it's Soviet orbit, which would've been easier and cheaper.