(Part 1 is here.)
Here’s how it works. Each district would be represented by 5 votes in the legislature (or possibly more, but fewer isn’t a good idea), each obviously worth 20% of the popular vote. If an election with two candidates goes roughly 60-40, the candidate with about 60% gets 3 of the votes in the legislature, and the other candidate gets 2. If it’s roughly 80-20, the result is 4-1. With more candidates, the math gets more complicated, and the fair way to determine how many votes each candidate gets is the Hare-Niemeyer method, which some countries use for their proportional representation systems. I know the idea of individuals with different amounts of power can seem unfair, but remember that the legislators are not there to represent themselves but their constituents, and someone with more constituents should have more power. It’s like owners of stock in a corporation having different numbers of votes at a shareholders’ meeting—those that have invested more get more say in how the investment is used.
The legislature would not be able to hold votes by acclamation, but this is not much of a concern, since votes can be taken in other ways. Electronic voting (which the U.S. House of Representatives already has) will, however, make it easy to cope with the varying numbers of votes held by legislators, each of whom should be required to cast all of his votes the same. So a legislator’s response to a question would still be “aye” or “nay”, but that response would be multiplied by the number of votes he holds, rather than, say, letting a legislator with 3 votes respond with “one aye, one nay and one abstention.”
Because a candidate would need at minimum only about 10% to get a vote in the legislature (due to rounding), this system begs for term limits. But rather than set an absolute limit, it can be designed to be based on how many votes the legislator holds. With 5 votes per district and 2-year terms, the formula I’d recommend is this: A candidate becomes ineligible for re-election if his terms exceed twice his current votes. So someone that never gets more than 1 vote could serve a maximum of 3 terms, 2 votes 5 terms, 3 votes 7 terms, 4 votes (rare) 9 terms, and 5 votes (unlikely) 11 terms. I would also include only the terms consecutive with the current term being served, so that legislators could serve for a while, go back to normal life, then serve again.
The really difficult aspect to deal with is how to replace a legislator in the middle of a term. In Colorado, where I live, if a member of the General Assembly leaves office early, the district committee of the same party chooses someone; there is no public election. That would be a viable system, unless the ex-legislator ran without party backing. The U.S. Constitution requires a popular election for representatives, even in special elections, so in that case, there are three options: 1) having what is essentially a primary vote within the party whose representative left office, with all the legislature votes going to the winner, 2) having an partially open election, but only among those voters affiliated with parties that don’t still have members serving that district, with multiple legislature votes being allocated to the representatives in the same manner as in the general election, and 3) having a fully open election with the legislature votes being distributed as in a general election. Number 2 seems the best, since in number 3 people that already got a representative could get another, and number 1 is pretty much undemocratic, and can’t deal with the case of an unaffiliated legislator. This would be up to the states for the most part, but Congress is allowed to override state laws concerning the time, manner and place of choosing members of Congress.