John Adams was not the successful administrator that Washington and Jefferson was;he was quite the absentee President and when he was in the capital attending to business, he would more times than not focus his energy in the wrong direction.
Many historians blame Hamilton for the demise of the Federalists and for Adams's re-election loss in 1800, but the biggest portion of the Federalist Party's downfall rests in the person of John Adams himself: he was the one who gave the Republicans the red meat that they wanted by pushing the Alien& Sedition Acts that was designed to punish Republican yellow-journalists who would often engage in personal attacks on Adams himself. The vindictiveness of JA's character is paramount here. Hamilton himself thought that the Alien&Sedition Acts was going too far - and he had endured more abuse from the Republican hacks than Adams ever had thought about. The mere proposal of these Acts were political suicide especially after Adams had broke the back of the Jacobin tendency of the Republicans in the 'XYZ Affair', and his re-election was a gimme. All that A&S did was to give the Republicans new life - something that both Jefferson and Hamilton realized.
Even without Hamilton's party- pamphlet circular attacking Adams as having an unstable personality (which the Republicans got hold of and published with glee) and unfit for the office of Presidency,John Adams would had lost in 1800 because of the Alien&Sedition Acts. True enough, I think it was partially a case of sour grapes with Hamilton since Adams had 86'd his last chance of military glory that he always craved, but the essence of said pamphlet also rang true: Adams was not up for the task of Chief Executive and Hamilton was hardly the first who realized that Adams was more than a bit neurotic. Adams's cantankerous, spiteful, and argumentative side of his persona was well known from his days in the Continental Congress in the 1770s; Benjamin Franklin realized that Adams was brilliant, but he "often left his senses" when political debate and discourses were engaged. The stories of Adams's temper-tantrums were reported by not a few, and one has the image of Hitler's conduct in the Der Bunker to compare with President Adams's behavior. The "right men for the job" was the one that preceded him, and the one who followed Adams into the executive office in 1800.
But let's give Adams some respect - he was a victim of circumstance. The fact of the matter is that there was no man in the Early Republic who could had been a good 2nd President of the United States. Jefferson in 1796 would had been a poor and even dangerous selection - he was still in his Jacobin phase - as he was the best one four years later. Hamilton would had not been a good choice in 1796 or at anytime(AH's talents were being an aide-de-camp, or an unofficial prime minister to a Chief Executive, and he was too controversial and divisive anyway). The 2nd President had to be always in Washington's shadow, and a more kinder and gentler man in Adams's place would had also been deemed a failure. John Adams, in a sense, took another proverbial bullet for the Team by even allowing himself to be elected President in '96 though he proved himself to be unfit for the Office.
John Adams retired to his farm in Braintree and lived another twenty-six years after he left the Presidency, writing his thoughts in a journal and later on reviving his friendship with Jefferson via a famed correspondence and he lived to see his son, John Quincy, elected President. Unlike most spawn from brilliant people, John Quincy Adams was more than a chip off the old man's block - Adams II was a certified genius, a wunderkind. But like his dad, JQA was a one-term President and not a successful one.
Though John Adams may rightly deserve an 'F' rating as President, few worked harder for the American Cause in the Revolution than he did, and he shall always be in the pantheon of the Founders. He had a keen legalistic mind and was a intuitive political scientist. Adams is the poster Founder of conservative thinkers like Russell Kirk, but I think that this is not a good judgment of John Adams: unlike Kirk, Adams was not an Anglophile; Adams had a distaste and fear of mobocracy, but being a New Englander with it's tradition of townhall democracy, Adams was and couldn't be undemocratic per se, even with a few Tory trappings here and there(Russell Kirk and his disciples should had moved to their beloved Great Britain and became genuine-article High Tories like Kirk's slobbering Anglophile hero, TS Eliot, did. I never fully understood why American conservatives thought that Russell Kirk was the Thing).
Adams was an astute Thinker and a leader among men - until he reached the Alpha political office, and the Presidency requires true Alphas. Adams came up more than a bit short, and it is a pity.