WASHINGTON — With a new promise of $20 million to help defeat Donald Trump, billionaire Facebook co-founder Dustin Moskovitz becomes one of the top Democratic donors of the election

The Silicon Valley entrepreneur calls the Republican presidential candidate dangerous and divisive and says his appeal to Americans who feel left behind is “quite possibly a deliberate con.”

By contrast, Moskovitz says, Democrats and their nominee, Hillary Clinton, are “running on a vision of optimism, pragmatism, inclusiveness and mutual benefit.”

Trump has struggled to gain traction among the tech elite, even though Republicans like House Speaker Paul Ryan have worked for years to strengthen the party’s relationship with the industry.

Oracle co-founder Larry Ellison gave $5 million to a super political action committee backing Republican Florida Sen. Marco Rubio in the primary. He has not made a presidential contribution since Rubio dropped out. Republican Meg Whitman, the chief executive officer of Hewlett Packard, so despises Trump that she has vowed to invest significant money in Clinton, whom she endorsed last month.

One of the few tech leaders to warm up to Trump is PayPal co-founder Peter Thiel, who spoke at the Republican National Convention in Cleveland and was a Trump delegate.

Yet the billionaire who pumped more than $2.4 million into efforts to elect Republican presidential candidate Ron Paul four years ago hadn’t written the Trump campaign so much as a $201 check as of July. 31, records show.

Trump has made few fundraising trips to Northern California, while Clinton was there a little over two weeks ago — and returns next week.

Moskovitz wrote about his planned Democratic contributions in a Thursday night posting on the website Medium titled “Compelled to Act.” Until now, Moskowitz had made only one federal campaign contribution, $5,200 in 2013 to Democrat Sean Eldridge. The husband of another Facebook co-founder, Eldridge unsuccessfully ran for a New York congressional seat.

Half of the $20 million Moskovitz and his wife, Cari Tuna, are giving will go to the League of Conservation Voters and to a political action committee called For Our Future. The latter group is a get-out-the-vote effort in battleground states that is paid for primarily by labor unions and hedge fund billionaire Tom Steyer.

Moskovitz and Tuna also are giving directly to Clinton’s campaign and to party committees helping Senate and congressional Democrats.

“As a nation, we need to figure out how to bring everyone with us, and we believe the Democratic platform currently is more aligned with ensuring that happens,” he wrote.

“In comparison, Donald Trump’s promises to this group are quite possibly a deliberate con, an attempt to rally energy and support without the ability or intention to deliver. His proposals are so implausible that the nation is forced to worry that his interest in the presidency might not even extend beyond winning a contest and promoting his personal brand.”

Only Steyer has given more this year to Democrats, campaign finance records show. The Californian has put up almost $40 million so far, to promote environmental issues and help elect Clinton and other Democrats.

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