"This has been a problem for years, if not decades," said Saurav Ghosh, director of campaign finance at the Campaign Legal Center.
Filings show President Joe Biden recently used donations from the Democratic National Committee to pay lawyers in a classified documents case.
For personal legal matters, such as Trump's New York business fraud case, experts say the use of political donations is prohibited.
With an additional three criminal cases awaiting trial dates, Trump's legal costs are expected to continue mounting.
In the week following the trial, Trump's team and the RNC reported having raised $141 million during the month of May, bolstered by millions raised in the aftermath of the verdict.
Persons:
Donald Trump, Trump, Saurav Ghosh, Joe Biden, Sen, Bob Menendez, Ghosh, we've
Organizations:
Trump, White House, Save, Democratic National Committee, FEC, RNC
Locations:
Manhattan, York