Wealthy donors to Vice President Kamala Harris’ campaign are quietly pushing her to drop a proposed policy on taxing unrealized capital gains, according to the New York Times.

Harris adopted a proposal by President Joe Biden to put a 25% tax on unrealized capital gains for individuals worth $100 million or more. Wealthy Harris donors are allegedly incredulous and have been pushing her to drop the policy ahead of the 2024 election amid concerns about the economic and political viability of the plan, according to The New York Times.

“There’s optimism that this can’t possibly be real,” Aaron Levie, chief executive of cloud-storage company Box, told the NYT. “Most people are waiting to hear from the Harris campaign. Is this a real proposal that is actually being pushed for — or was this something that was inherited from Biden?”

Harris campaign spokesman Charles Kretchmer Lutvak told the NYT that the policy was to get billionaires to pay a “fair share” in taxes. Harris also voiced her support for Biden’s other tax hike proposals for the 2025 budget that cost a total of approximately $5 trillion, according to the Cato Institute.

Levine has donated $30,000 to the campaign and plans to donate more, but said that his Silicon Valley colleagues see the capital gains proposal as “punitive,” according to the NYT. Some donors have privately said that Harris’ policy positions in general are more flexible than Biden’s, sustaining hopes that Harris may back off the proposal.

“In my world, yes, I do hear about it and there is concern,” Charles Myers, a Harris fundraiser and founder of Signum Global Advisors told the NYT. “I think almost every person who would raise it as a concern understands that it would never pass Congress even if it’s a Democratic sweep.”

More than 100 Silicon Valley investors pledged support for Harris in July as “VCs for Harris,” which include former Dallas Mavericks Owner Mark Cuban, LinkedIn Founder Reid Hoffman and Khosla Ventures founder Vinod Khosla, according to the NYT. Approximately 75% of members believe that “taxing unrealized capital gains will stifle innovation,” according to an internal survey among its members.

“This [proposal] is beyond insane,” E.J. Antoni, a public finance economist at the Heritage Foundation’s Grover M. Hermann Center for the Federal Budget, told Fox News. “This proposal by Harris’ handlers would literally force people to sell off a portion of their investments every year in order to pay the taxes due on unrealized gains. Until an asset is actually sold, any increase in value is purely speculative. It isn’t real, hence the classification of unrealized. The people pushing this idea are demonstrating their complete and total ignorance of both finance and economics.”

The Harris Campaign did not immediately respond to the Daily Caller News Foundation’s request for comment.