Horseshoes and Hand Grenades?

I think the underlying fundamental question that Delillo is asserting is, does Kennedy have to die for Cuba? At the midway point of the novel, there are two answers to this question.  Mackey believes that he does, Win Everett thinks he doesn't.  Win originally comes up with the conspiracy, with the stated outcome of a near miss of the President from a sniper's bullet.  It has to be close enough that it looks like Cuban intelligence sent someone to do the job, but not so close as to actually endanger the President.  Already there has been dramatic ironic tensions as Nicholas Branch has written that Raymo and Frank haven't been told to miss, andCarmine Lotta, the man unknowingly funding the conspiracy, has stated he wants to take the head off the snake (AKA JFK).  Essentially, the very thing Everett fears, his conspiracy growing legs of its own independent of him, is happening.  He's lost control from his suburban home in Texas, the plot is now moving without his impetus or knowledge.

But beyond the individual, personal motives for and against actually killing the President, is it objectively necessary?  Looking at this historically, granted with the benefits of hindsight the answer is a firm no.  U.S. policy has never been more directly counter the Castro government in Cuba than during the Kennedy administration.  When Johnson takes over in November '63, his attention turns towards his Great Society, the Vietnam War, and the Civil Rights Movement.  Cuba effectively disappears from the political debate. Now granted, the Kennedy Assassination was not tied to the Cubans, and if it were I think certainly that would have made a difference, but no other President had as much at stake as Kennedy with regards to Cuba.  Cuba was his biggest embarrassment, and he already had a inferiority complex because of his lack of governmental experience, so he would've done anything to turn it into a win.

If Kennedy had survived that day in Dallas, he would have kept after Cuba.  Publicly the U.S. won the Cuban Missile Crisis, so there would be no reason for him not to keep pressing that advantage.  He was a pretty emotional president, so if he thought Castro had come after him, the threat of the Soviets probably wouldn't have been enough of a deterrent to invade Cuba.  Plus the American public's support for Kennedy would've been galvanized to the point they would have followed him anyway.  I guess then, my conclusion is that it would have been better for the pro-Cuban interventionists for Kennedy to have lived and that Everitt's plot in its original form would have been the best outcome for the whole movement.  In my thinking Mackey seems not only shortsighted but also selfish for letting his personal feelings get in the way of the larger interests he claims to be fighting for.