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.
rank. the place in a series occupied by a value when the series has been set in order according to a particular trait, usually size. Called also order statistic. rank sum test. nonparametrical statistical test used to compare two methods by seeing if one method contributes more to the higher ranked values.