Analysis by Chris Cillizza, CNN Editor-at-large

(CNN) -- The New York Times published a story over the weekend detailing the "shadow" campaign underway among ambitious Republicans to be prepared in the event that President Donald Trump doesn't run for a second term in 2020.

The story mentioned that Vice President Mike Pence's "schedule is so full of political events that Republicans joke that he is acting more like a second-term vice president hoping to clear the field than a No. 2 sworn in a little over six months ago."

And that Pence -- via aides -- is making sure he's first in line if Trump bows out; "multiple advisers to Mr. Pence have already intimated to party donors that he would plan to run if Mr. Trump did not," wrote Timesmen Jonathan Martin and Alex Burns.

In reaction to the story, Pence -- and this is no exaggeration -- went bananas. He released a statement through the vice president's office insisting that the Times story was "disgraceful and offensive to me, my family, and our entire team." He also called it "laughable and absurd" that he was doing anything in regard to 2020 other than working to ensure Trump wins a second term.

Pence's reaction was far more aggressive than the others -- Sens. Tom Cotton of Arkansas and Ben Sasse of Nebraska, as well as Ohio Gov. John Kasich -- mentioned in the story as laying the groundwork to be ready if Trump exits after a single term. (This may all be a moot conversation, given that Trump insists he is running in 2020 and has already raised about $17 million for his re-election race.)

Pence's (over)reaction raises a simple question: Why?

And the answer starts with "Donald" and ends with "Trump."

Pence's political fortunes are 100% tied to Trump. They have been since the day the then-Indiana governor said "yes" to Trump's offer to share the ticket. On that day, Pence became a stranger to the GOP political establishment that was still very leery of the idea of Trump as the party nominee.

That estrangement has only continued since Trump became President. Pence has been an unquestioning Trump ally at every turn, insisting that the President knows exactly what he's doing -- and either ignoring or rebutting the criticism leveled at Trump by many of the people Pence once served with. (Remember that Pence was a member of the House Republican leadership before leaving to run for governor in 2012.)

Pence, in other words, is all in on Trump. His path to become president is to be the Trump-endorsed candidate, the heir to the movement that Trump built during the 2016 campaign. And to do that, Pence absolutely must make sure there is never any distance between him and the President.

It's doubly important for no one to be able to slip a piece of paper between Pence and the President because the President is Donald Trump. Trump is forever watching to make sure no one in his world is eclipsing him -- or even trying to. The unforgivable sin in Trump's world isn't saying or doing impolitic things, it's appearing to be something short of entirely loyal.

That's why a story like the one in the Times on Sunday is so potentially damaging for Pence. Pence knows Trump reads the Times; it's his home paper and the one he cares the most about. And Pence knows that if he appears to be angling in any way, shape or form to be ready in 2020, Trump will give him the pariah treatment. (That treatment should probably be renamed "The Sessions.")

And so, Pence goes on offense -- releasing a total and complete denial to make sure that as soon as Trump reads, sees or hears about the story, the President also reads, sees or hears about Pence's denial of it.

Pence's audience for this statement is just one person: The guy who sits in the Oval Office. And he's smart enough to understand that that's the only opinion that really matters to his political future.