Political parties exist to secure responsible government and to execute the will of the people. From these great tasks both of the old parties have turned aside. Instead of instruments to promote the general welfare, they have become the tools of corrupt interests which use them impartially to serve their selfish purposes. Behind the ostensible government sits enthroned an invisible government owing no allegiance and acknowledging no responsibility to the people. To destroy this invisible government, to dissolve the unholy alliance between corrupt business and corrupt politics is the first task of the statesmanship of the day.

Theodore Roosevelt (1858-1919) American politician, statesman, conservationist, writer, US President (1901-1909)

Progressive Party Platform (Aug 1912)
    (Source)

Party platform attributed to Roosevelt. Also restated by him in An Autobiography, ch. 15 (1913):

Behind the ostensible Government sits enthroned an invisible Government, owing no allegiance and acknowledging no responsibility to the people. To destroy this invisible Government, to dissolve the unholy alliance between corrupt business and corrupt politics, is the first task of the statesmanship of the day. ... This country belongs to the people. Its resources, its business, its laws, its institutions, should be utilized, maintained, or altered in whatever manner will best promote the general interest.

Released as a sound recording, "The Progressive Covenant With The People," during the campaign for locations where Roosevelt was unable to visit to speak.