In 2012, candidates needed either one percent or 500 signatures (whichever was lower) from Democrats in each of the state's 50-plus congressional districts. They had two months to do so -- which, particularly if you're hoping to keep expenses under $5,000, is a time crunch. Other states work similarly; some don't.
A contemporary definition of rank-and-file is prevalent in labor union vernacular when referring to general membership and not union leaders. Rank-and-file generally means the employee doesn't occupy a high-level position within the organization.
We can still rank ordinal responses. Rank is an interval scale (intervals on rank have the same meaning everywhere in a given ranking). Mean rank (for example for different treatments) also has a meaning on the ranking scale, and can be used, for example, as estimates of a population mean rank.