Mardukes: I don't know exactly what you mean by "resource limitations." But late game hyper-expansion requires a heavy investment in Engineers, with railroads an important accelerator to expansion.
Basically, it is with the establishment of a Power Democracy that I am able to achieve hyper-expansion. Because I employ a specific Modernization process, my "core" is already developed with an integrated railway and ferry system, and Supermarkets and farmland to support Engineers when I achieve the Corporation. With the advent of Freight units, the Power Democracy takes off and hyper-expansion becomes possible. By using a liberal application of Trade to provide extra income (and cover scientific advancement), I am able to rush build Engineers while having all cities in a state of WLKD so that there is no decrease in net population. The only real limitation to hyper-expansion at this point is whether or not you're going to knock out the AI civs before, during, or after hyper-expansion. It is possible to achieve hyper-expansion while engaging in world conquest, but this usually requires diverting both Engineers and money to support military campaigning.
Hope this answers you're question.
Ps. How about them Cubbies? Baker seems to be instilling them with some attitude!