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-and-file employees are the lifeblood of organizational success. Without rank-and-file employees, many companies' production levels would dwindle to nothing because rank-and-file employees often are solely responsible for turning out the products that companies sell. However, often little attention is paid to employees who make the most significant contributions to the business.