Question

However [political parties] may now and then answer popular ends, they are likely in the course of time and things, to become potent engines, by which cunning, ambitious, and unprincipled men will be enabled to subvert the power of the people and to usurp for themselves the reins of government, destroying afterwards the very engines which have lifted them to unjust dominion.

Could someone explain what Washington is saying in this quote?

Answer 1

He's saying that political parties can be used to promote private interests, mainly to make it easier to make money by manipulating laws, instead of public interest (as in the interests of ALL the people, not just a few). For example, if you borrow money to buy a new car, if the bankers controlled the government and the laws, they might charge you VERY high interest rates. If the law, in the interest of you and other borrowers, made that illegal, it would be to the benefit of everyone. Unlimited interest rates would hurt everyone else, but help the bankers make more money for themselves. Or if the drug industry wants to charge higher prices in the United States than they do in Canada, the drug industry could get the law to prohibit U.S. people from buying cheaper drugs in Canada. That really is happening now. Political parties can be used for purposes like that, or Washington was afraid they could be.

Answer 2

If you still don't understand, please say so and I'll try again. :)