These days, former presidents tend to keep their noses out of the business of the current president, but that wasn’t always the case. When Abraham Lincoln became a candidate for the White House, the five living ex-presidents opposed his candidacy for various reasons (for those keeping count: Van Buren, Tyler, Fillmore, Pierce, and Buchanan). Once Lincoln was elected, they all second-guessed him in various ways and with various degrees of publicity and effectiveness.
Former president Millard Fillmore probably sums it up best: “Unsolicited advice is often deemed officious if not offensive, and therefore is quite likely to do harm as good.”
I don’t typically repost links here (although we do more of that on our Facebook page, so you should be following us there if you’re not!). However, DeRose published a feature in The Washington Post that summarizes his book. It’s definitely worth checking out.
(As a related aside: Van Buren died during the war, while the outcome was still very much in doubt. As it happened, I spent a little time with “Old Kinderhook” exploring that story on the sesquicentennial of his death. You can check out that story here.)