Hedge fund manager Paul Singer, regarded as one of the wealthiest and most influential Republican donors, on Monday signaled that he will support neither Donald Trump nor Hillary Clinton in the general election this fall, NRO reported.

Speaking at a dinner hosted by the Manhattan Institute, a think tank where he serves as chairman of the board, in Manhattan on Monday, Singer reportedly said conservatives must “stand up for what we believe, which is not embodied by either choice on the menu in November.”

According to the NY Times, Singer described Trump and Clinton as “signs of philosophical, policy and political exhaustion” who reflect “the politics of anger and nostalgia, of visceral responses.” He reportedly told the crowd it’s unclear what Trump stands for and characterized his views as a “blizzard” of contradictions.

Singer supported Marco Rubio in the Republican primaries. After Rubio suspended his campaign for president in March, Singer contributed to the anti-Trump movement. In 2012, he raised more than $3 million for Mitt Romney during the primary and general election.

Also on Monday, Rubio shut down rumors that he’s being considered as a potential running mate for Trump. “While Republican voters have chosen Donald Trump as the presumptive GOP nominee, my previously stated reservations about his campaign and concerns with many of his policies remain unchanged,” Rubio stated in a message to his 1.4 million followers on Facebook. “He will be best served by a running mate and by surrogates who fully embrace his campaign. As such, I have never sought, will not seek and do not want to be considered for Vice President.“

Las Vegas casino mogul Sheldon Adelson on Thursday expressed his support for Trump. “Yes, I’m a Republican, he’s a Republican. He’s our nominee. Whoever the nominee would turn out to be, any one of the 17 — he was one of the 17. He won fair and square,” Adelson told reporters while attending the World Values Network gala in New York City on Thursday. “I think that Donald Trump will be good for Israel.”