A data-rich, eye-opening look at how, when, and why political fundraising is consequential. Over the last two decades, the number of competitive congressional races has declined precipitously. Yet candidates and officeholders dial for more and more dollars each election, and they do so earlier and earlier in the campaign cycle. In The Money Signal, Danielle M. Thomsen offers a new perspective on the role of money in politics. She shows that fundraising matters because it is widely used as an indicator of a candidate's viability and strength, which shapes subsequent donations, dropout decisions, media attention, and rewards in office. Put simply, money is a focal point that candidates, donors, journalists, and party leaders rally around. For candidates, fundraising is a highly public form of self-presentation that pays dividends long before the election and well after the votes are cast. Thomsen draws on comprehensive fundraising data that spans more than four decades, in addition to interviews, surveys of candidates and donors, newspaper coverage, committee assignments, and legislative success. The Money Signal highlights the numerous ways that dollars influence the perceptions and behavior of key actors and observers throughout the election cycle.