The move to make a quicker dash for campaign funds, according to people close to Mrs. Clinton’s campaign, was driven by the Democratic candidate’s concern about the amount of money that Jeb Bush had been raising for his super PAC.

Declared presidential candidates are precluded from coordinating with super PACs, which emerged on the political landscape following the Citizens United decision by the U.S. Supreme Court in 2010. Mr. Bush, as a non-declared candidate who is also out of office, faces no such restrictions, his allies argue. His critics have accused him of walking up to the line on campaign finance regulations, but he has insisted his team is complying with the law…

Mr. Bush is raising unlimited super PAC dollars, while Mrs. Clinton is raising money in increments of $2,700 for her campaign. But, according to two people who have been privy to the conversations, Mrs. Clinton has privately complained about Mr. Bush and his super PAC fund-raising, including the fact that he is delaying declaring his candidacy as long as possible so he can keep raising for the outside group that will back him.