Mr. Harrison was one of the few Silicon Valley Republicans willing to chat openly about their options this year. Virtually every prominent Republican in the industry whom I called declined to comment or was willing to speak only anonymously about the strained connection between the tech industry and the Republican Party.

To people who work in the industry, the diminished state of the Republican Party among techies may not come as a surprise. Though Silicon Valley has a reputation for libertarian leanings, most people in the industry tend to identify with Democrats. Both in votes and in fund-raising, President Obama trounced Mr. Romney and Mr. McCain in Silicon Valley.

Greg Ferenstein, author of “The Age of Optimists,” a book about tech and politics, has studied start-up founders’ political views. He has found that while founders tend to support some libertarian points of view (they are for free trade and tend to be skeptical of labor unions), they are generally aligned with Democrats on many major policy areas. They are for increased immigration, for greater environmental protections, for more government spending on research and infrastructure, and for health care mandates like the one in the Affordable Care Act, among other ideas.

Image Credit... Stuart Goldenberg

People in Silicon Valley “are supporting policies that are very much pro-capitalism and pro-government at the same time,” Mr. Ferenstein wrote last year. He added, “No, Silicon Valley is not a libertarian hotbed; rather, we are witnessing the rise of an entirely new type of Democrat.”

A few Republicans in tech told me they had been enthusiastic that this year’s slate of presidential candidates could remake the Republican brand among techies. Jeb Bush, Chris Christie, Marco Rubio, John Kasich and Rand Paul all seemed personally comfortable with tech (Governor Bush’s 2006 official portrait shows him standing next to his cherished BlackBerry), and several had expressed interest in addressing crucial policy issues that were of concern to some in the industry. For instance, appointments at the Federal Trade Commission, the Federal Communications Commission and the Department of Labor might have given the industry some of what it wanted on issues having to do with labor rulings and privacy and antitrust investigations.

Then Mr. Trump won the nomination and the Republicans’ brand in Silicon Valley fell through the floor. Though he runs a popular Twitter account, the New York businessman is widely seen as a tech ignoramus by people in the industry. Last year, in response to the threat posed by terrorists’ recruiting people online, Mr. Trump said he would enlist the Microsoft co-founder Bill Gates to help him “close up” essential parts of the internet — an idea that was mocked as ridiculously unworkable. He also said he would force Apple to make iPhones in the United States, has threatened Amazon with an antitrust investigation and proposed boycotting Apple because of its standoff with the government over encryption — none of which won him friends in tech.