H.L. Mencken (born 1880 - died 1956) was a journalist, satirist, critic, and a registered Democrat.
He wrote the editorial below while working for the Baltimore Evening Sun, which appeared in the July 26, 1920 edition.
"As democracy is perfected, the office of the President represents, more and more closely, the inner soul of the people. On some great and glorious day, the plain folks of the land will reach their heart's desire at last and the White House will be occupied by a downright fool and complete narcissistic moron."
-- H.L. Mencken, the Baltimore Evening Sun, July 26, 1920
So it was written, and so it has come to pass ...
SNOPES opined further on this:
Regardless of the quotation's applicability to modern U.S. presidents, the subject at hand here is the question of whether it really issued from the pen of H.L. Mencken or whether (as is often the case) it is a modern sentiment by some contemporary, anonymous wit which has been falsely attributed to a famous pithy-but-dead commentator in order to lend it credence.
In this case the attribution to Henry Louis Mencken, a prominent newspaperman and political commentator during the first half of the 20th century, is accurate. Writing for the Baltimore Evening Sun on 26 July 1920, in an article entitled "Bayard vs. Lionheart" (and reprinted in the book On Politics: A Carnival of Buncombe), Mencken cynically opined on the difficulties of good men reaching national office when the scale of their campaigns precluded them from directly reaching out to large segments of the voting public:
"The larger the mob, the harder the test. In small areas, before small electorates, a first-rate man occasionally fights his way through, carrying even the mob with him by force of his personality. But when the field is nationwide, and the fight must be waged chiefly at second and third hand, and the force of personality cannot so readily make itself felt, then all the odds are on the man who is, intrinsically, the most devious and mediocre — the man who can most easily adeptly disperse the notion that his mind is a virtual vacuum.
The Presidency tends, year by year, to go to such men. As democracy is perfected, the office represents, more and more closely, the inner soul of the people. We move toward a lofty ideal. On some great and glorious day the plain folks of the land will reach their heart's desire at last, and the White House will be adorned by a downright moron."
Read more at http://www.snopes.com/politics/quotes/whitehousemoron.asp#vhWd1BbBDXCuFe2L.99