What we have now as a legislative process came about as the replacement (however gradually, and fitfully) of a system which once upon a time "ran-like-clockwork" because, unlike today, there was such a well-organized party system with such awesome and thorough control over who was to be a House or Senate candidate, that, very few if any members --and certainly no members who could be described as "ordinary rank-and-file") ever came to hold office without the blessing of the leadership to whom they were completely beholden.

   For Republicans, this was nothing other than simply political business as usual.  For Democrats, in, for example the heydays of New York's Tammany Hall, it was distinguished from the Republican brand of graft as being "honest graft", in a feat of moral and intellectual acrobatics which is not very different in its base from what some today do to explain, excuse and apologize for the system that prevails.  In  William Riordan's classic text, Plunkitt of Tammany Hall [Plunkitt of Tammany Hall: A Series of Plain Talks on Very Practical Politics (New York: E.P. Dutton, 1963) ], referring to George Washington Plunkitt (1842 - 1924), famous for having said, "I seen my opportunities and I took 'em" (as any Mafia hit-man could as easily claim), we're told of an occasion in which it's admitted that the forces for reform should actually prevail, but that it has to be understood that the time is not yet right and ripe for such reform.  Such a explanation may have been made entirely unselfconsciously.  In the time---unlike in our advanced day---everyone took these things for granted.

 e.g.

  as present-day casebook example of a politician offering a rationale:

  "We're trying to do too much at once," Lieberman said. "To put this government-created, government-run insurance company on top of everything else is just asking for trouble for the taxpayer, for the premium payer and for the national debt. I don't think we need it now."

  http://thehill.com/homenews/senate/65105-reid-doesnt-have-health-votes-yet