As her campaign limps into Super Tuesday, Massachusetts Senator Elizabeth Warren is receiving millions of dollars in help from the kind of outside money group she has repeatedly decried, underscoring the tough realities of a primary contest featuring two self-funded billionaires and a collection of rivals benefiting from political-action committee money. Persist PAC, a super PAC that officially formed several days before the Nevada caucuses to support Warren’s campaign, announced Thursday it would spend $9 million in advertising across television markets in three Super Tuesday states: California, Texas and Warren’s home state of Massachusetts.