… is from page 87 of the 2009 edition of the incomparable H.L. Mencken’s 1926 volume, Notes on Democracy :
The bargaining [of politicians for votes] is conducted to the tune of affecting rhetoric, with music by the choir, but it is as simple and sordid at bottom as the sale of a mule. It lies quite outside the bounds of honour, and even of common decency. It is a combat between jackals and jackasses.