Hillary Clinton supporters are targeting former Jeb Bush donors

Hillary Clinton supporters have reportedly been courting top Bush family donors in recent days, claiming the Democratic front-runner is a better choice for them than presumptive Republican nominee

Donald Trump, according to a report from POLITICO.

A person close to the campaign told POLITICO Clinton staffers compiled a list of donors who had backed Jeb Bush, as well as other former GOP candidates, "but wanted to wait until Trump locked down the nomination before beginning to make the calls."

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A Clinton spokesperson claimed it was not an official campaign directive, but said he "would not be at all surprised if our supporters are doing it on their own."

This comes days after both Presidents George H.W. Bush and George W. Bush both refused to endorse Trump. Several other major GOP figures, including House Speaker Paul Ryan and Mitt Romney, have spoken out against the real-estate mogul since it became clear he had locked down the party's nomination.

See more of Clinton on the 2016 campaign trail:

The 2016 election is shaping up to be the most expensive in history. Donald Trump told NBC News on Wednesday he had begun working with the Republican party to set up a fundraising network with the goal of raising $1 billion. On Thursday Trump named Steven Mnuchin, a former partner at Goldman Sachs, as his national finance chair.

The move to begin fundraising is a departure from his long-held claim that he was was largely self-funding his campaign and therefore not beholden to special interests -- which The Wall Street Journal points out means he will "no longer have that line of attack to use against his Democratic opponent."