Final answer:
The main source of campaign funds is from individual donors. Candidates often use polls to identify their greatest sources of public support.
Step-by-step explanation:
The main source of campaign funds is from individual donors rather than from political action committees (PACs) and political parties.
According to the Center for Responsive Politics, the majority of direct campaign contributions come from individual donors. PACs and political parties contribute a smaller portion of the funds.
Candidates often use polls and pollsters to identify their greatest sources of public support, which helps them determine their fundraising strategy.