Hillary Clinton, the frontrunner for the Democratic nomination for president, said her campaign expects to have raised more than $45m in her first three months as a candidate, beating President Barack Obama’s previous record and marking her financial dominance over the Democratic field.

Campaign officials said on Wednesday that the amount raised during the quarter ended in June was greater than their own expectations, with 91 per cent of donations made at below $100.

That is an important indicator that Mrs Clinton’s strategy of building an infrastructure to target the individual, small-dollar donors who are vital to a successful grassroots campaign finance operation is paying off. However, the total number of donations may fall short of the 50,000 target the campaign had sought.