This will be a ongoing topic. This isn't really about political issues. This is about structure of government: philosophy and civics. It's about ideas that generally don't receive much discussion in that civics class you probably took in high school.
Proposal: All national elected government positions should be voted for by the whole population, rather than on a by-state basis.
Reasoning: While federalism has its purposes, the representation by states was primarily a product of the fact that, at the time of the founding of our nation, individual states did have some sovereignty. They could easily have decided not to join the Union without a constitution that respected that sovereignty. In modern times, however, the national government is now where people primarily look to fulfill the necessary roles a government performs. People move more, and feel tied to their state less. People participate and are interested in the national government far more than state or local governments.
Advantages: Potentially, a significant decrease in localized pork-barrel projects. It would free congressman to vote for what's best for the nation, not what's best for their home state/district. It might also increase voter interest in elections for positions other than President, as people mostly on pay attention to national politics.
Disadvantages: Too hard for voters to know everything about the candidates. The media attention that makes a presidential race work in America can't possibly be stretched across all members of congress being elected in a given election.
Compromise: It's clearly too far-fetched to elect our Representatives at-large. Senators, however, might be feasible. A Senator was initially intended to be a representative more of their state government than of the people, but since the Constitution was amended to proscribe direct election of Senators, that purpose no longer applies. So why not know make the Senate the chamber of congress representing the people nationally, rather than by state? Obviously, a lot of theory work on how apportionment should go with this change would be required. At a minimum, I think some number of senators, perhaps additional ones, should be at-large national senators, rather than representatives of a particular state.