Here is context for my question: I am a student studying political science. I am researching policy that could be used to dismantle the stranglehold that the Democratic and Republican parties have on American elections. In some ways it seems that our national electoral system is engineered for the success of only these two parties. In recent years, some ideas have been floated to make third party campaigns more viable, such as ranked choice voting. However, maybe I think these ideas don't go far enough to dismantle the two-party system. Let's say I have one objective: Transition the United States House of Representatives to be elected by a system of proportional representation. This applies only to the US House, not the Senate, not state assemblies, not anything else. Just the House of Representatives.
(Here is my understanding of proportional representation, I would love more insight: Proportional representation is an electoral system used by democracies all around the world, but not by the United States. We use a "first-past-the-post" system to elect representatives. In proportional representation, everyone within a state would vote for a party, not a candidate. Let's say, in the state of Colorado, the Democratic Party gets 35% of the vote, the Republican Party gets 35%, the Libertarian Party gets 15%, and the Green Party gets 15%. Each of those parties would get a number of Colorado's US House seats proportional to their share of the vote. For example, the Libertarian Party would get 15% of the seats.)
So my objective is to transition the House of Representatives to a system of proportional representation. To my understanding, our "first-past-the-post" system is federally reinforced, since "PL 2 USC 2c" mandates that representatives be elected via single-member districts. As far as I know, as long as these single-member districts exist, we cannot have proportional representation.
What is "PL 2 USC 2c?" What does it mean? What does it legally mandate?
What is the legislative process for overturning or editing an article of public code like "PL 2 USC 2c?"
Can it be edited to let states choose how to elect their representatives, so that proportional representation can be implemented on a state-by-state basis?
Are there Constitutional obstacles to proportional representation and specifically to editing "PL 2 USC 2c" in this way?
Obviously, in practice, these proposals would be met with resistance from legislators, and accomplishing this would be a bureaucratic nightmare. I am not interested in hearing about those kinds of obstacles, I am simply wondering if this can be accomplished legally. Thank you all so much.