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.
1. a social or official position or standing, as in the armed forces: the rank of captain. 2. high position or station: a person of rank. 3. relative position or standing: a writer of the first rank. 4. a row or series of things or persons. 5. a number of persons forming a separate class, as in a social hierarchy.