… is from page 134 of the second edition (1861) of John Stuart Mill’s Considerations on Representative Government: 
Suppose, then, that, in a country governed by equal and universal suffrage, there is a contested election in every constituency, and every election is carried by a small majority. The Parliament thus brought together represents little more than a bare majority of the people. This Parliament proceeds to legislate, and adopts important measures by a bare majority of itself. What guaranty is there that these measures accord with the wishes of a majority of the people? Nearly half the electors, having been outvoted at the hustings, have had no influence at all in the decision; and the whole of these may be, a majority of them probably are, hostile to the measures, having voted against those by whom they have been carried. Of the remaining electors, nearly half have chosen representatives who, by supposition, have voted against the measures. It is possible, therefore, and even probable, that the opinion which has prevailed was agreeable only to a minority of the nation, though a majority of that portion of it whom the institutions of the country have erected into a ruling class. If democracy means the certain ascendancy of the majority, there are no means of insuring that, but by allowing every individual figure to tell equally in the summing up. Any minority left out, either purposely or by the play of the machinery, gives the power not to the majority, but to a minority in some other part of the scale.