"There can be no effective control of corporations while their political activity remains."
-- Theodore Roosevelt, speech, August 31, 1910

Below is the exact and full text of an old Wisconsin law constraining corporations from participating in politics (they can't vote, the logic went - what the heck are they doing in politics?). 

It's typical of laws that virtually every state in the USA carried until Supreme Court decisions based on the 1886 Santa Clara mistake were used to strike them down. Here's the old Wisconsin law:

Political contributions by corporations. No corporation doing business in this state shall pay or contribute, or offer consent or agree to pay or contribute, directly or indirectly, any money, property, free service of its officers or employees or thing of value to any political party, organization, committee or individual for any political purpose whatsoever, or for the purpose of influencing legislation of any kind, or to promote or defeat the candidacy of any person for nomination, appointment or election to any political office.

Penalty. Any officer, employee, agent or attorney or other representative of any corporation, acting for and in behalf of such corporation, who shall violate this act, shall be punished upon conviction by a fine of not less than one hundred nor more than five thousand dollars, or by imprisonment in the state prison for a period of not less than one nor more than five years, or by both such fine and imprisonment in the discretion of the court or judge before whom such conviction is had and if the corporation shall be subject to a penalty then by forfeiture in double the amount of any fine and if a domestic corporation it may be dissolved, if after a proper proceeding upon quo warranto, in either the circuit or supreme court of the state to be prosecuted by the attorney general of the state, the court shall find and give judgment that section 1 of this act has been violated as charged, and if a foreign or non-resident corporation its right to do business in this state may be declared forfeited. (Emphasis added.)

Until the doctrine that corporations are "persons" with "rights" is changed back to the way US laws were from the American Revolution until recently - so corporations will again, like unions still are today, become "artificial entities" with "privileges" determinde by We, The People - our democracy will continue to be in peril.

(The Wisconsin law was from SECTION 4479a [Sec. 1, ch. 492, 1905] and this law was only struck down in Wisconsin in 1953.)