Much has been made, in recent years, of the support offered by prominent Silicon Valley figures to Democratic politicians. Before he became C.E.O. of Google, in 2001, Eric Schmidt backed Al Gore’s 2000 Presidential run, and he was a prominent supporter of Barack Obama in 2008, even going on the campaign trail with the candidate. In the run-up to the 2012 election, Paul Graham, a co-founder of the startup incubator YCombinator, conducted an informal poll of people he considered leaders in Silicon Valley; of the twenty-four respondents, seventeen supported or were leaning toward Obama. That seeming coziness has continued during Obama’s second term. In September, for example, the President named Megan Smith, a former Google vice-president, as his chief technology officer, while the Facebook C.O.O. Sheryl Sandberg has sat on the President’s Council on Jobs and Competitiveness since being appointed in 2011.

Yet, according to the Center for Responsive Politics, Republicans have received the majority—about fifty-three per cent—of the more than six million dollars contributed to candidates for federal office this election cycle by corporate political-action committees in the “Computers/Internet” sector, a category that includes PACs representing Amazon, Facebook, Google, and Microsoft. Google’s lobbying organization, NetPAC, is the largest such PAC, and has grown at an astonishing rate: it was created in 2006 and spent less than forty thousand dollars on that year’s election; in the 2014 cycle, it has spent $1.6 million, with more going to Republicans than to Democrats. Facebook’s PAC has spent nearly five hundred thousand dollars on the 2014 election, and has also sent more money to Republicans (John Boehner, the Speaker of the House, is its top recipient) than to Democrats.

In November, Nathan Heller wrote of “the contradictions and hypocrisies” evident in the biographies of powerful Silicon Valley company founders—that is, the tension between their idealistic rebellions against existing power structures and their reliance on those structures to get ahead. This same tension appears to be at work in the approach tech companies are taking to funding candidates for Tuesday’s election.

To be sure, many prominent Silicon Valley figures are maintaining a commitment to the Democrats—the most talked-about political donor from the region, by far, is Tom Steyer, the hedge-fund founder and environmentalist. Steyer has spent, via his NextGen Climate Action PAC, more than sixty million dollars—more than any other individual has donated to PACs, at least when it comes to publicly disclosed contributions—to support the campaigns of candidates who share his views on climate change (and to defeat those who don’t). The LinkedIn co-founder Reid Hoffman and the entrepreneur Sean Parker have also attracted attention for their contributions to the Mayday PAC, which was founded by the Harvard University law professor Lawrence Lessig to promote candidates who are interested in campaign-finance reform (and to defeat those who aren’t). The independent expenditures of Steyer’s super PAC have been entirely in support of Democrats or against Republicans; nearly eighty per cent of the independent expenditures from the Mayday PAC have been for Democrats or against Republicans, while the rest has gone to support G.O.P. candidates.

But, as donations by the region’s corporate PACs show, this seeming preference for the Democrats isn’t true of the sector as a whole. “Most industries are not going to get biased for one side or another,” Russ Choma, a money-in-politics reporter at the Center for Responsive Politics, told me. “When you look at the really well-developed influence operations, you see this trend where, when the Democrats are in power, they give money to Democrats, and when the Republicans are in power, they give money to Republicans.” He added, “It’s this really pragmatic approach, which may clash a little bit with the public perception of the ethos of some of these companies.”

Donations made to Fred Upton, an incumbent Republican congressman running for reëlection in Michigan’s Sixth District, show how the companies’ goals are sometimes at odds with those of other organizations funded by Silicon Valley leaders. Upton, who has been in Congress since 1987, is the chairman of the Committee on Energy and Commerce, which oversees telecommunications, consumer protection, and interstate and foreign commerce, among other areas. Upton is one of three lawmakers who have received twelve thousand five hundred dollars each from Google’s PAC, more than it has given to any other candidate. (The others are Nancy Pelosi, the Democratic minority leader of the House, from California, and Steny Hoyer, the House Democratic Whip, from Maryland.) Not coincidentally, Google’s main lobbying concerns this year, according to public data gathered by the Center for Responsive Politics, are copyright, patent, and trademark matters; telecommunications; and labor, antitrust, and workplace issues—all areas over which Upton has a great deal of influence. He has been an important supporter, for instance, of pursuing immigration reform, which U.S. tech companies are seeking because they would like to hire more foreign workers.

Thanks partly to support from Google and other companies, Upton had seemed sure to win reëlection. Then, in recent weeks, the Mayday PAC spent more than two million dollars to unseat him, including on television ads. The PAC called him the “worst of the worst” and a lawmaker who “consistently puts big-money donors ahead of his constituents.” Mayday is instead backing Paul Clements, a previously unheralded professor at Western Michigan University who is running as a Democrat and supports campaign-finance reform. (Upton has said that he also supports campaign-finance reform.) The ads may be working. Last week, Clements’s campaign released polling results showing that Clements was behind Upton by only four percentage points, compared with a fifteen-point gap in early October. The Cook Political Report lowered Upton’s chances of winning from “solid” to “likely.”

On Friday, Amy Schatz, of the tech blog Recode, called Mayday’s decision “an odd tactic,” given Upton’s ties to the tech industry and his avowed support for campaign-finance reform; she quoted an unnamed Internet-industry lobbyist speaking about the Mayday PAC: “If I was a donor who gave five dollars to this group or one who gave $500,000 to this group, I’d be asking for my money back.” Parker and Hoffman are also supporters of FWD.us, the group created by Mark Zuckerberg, the Facebook C.E.O., to push for immigration reform. In mid-October, one Fortune headline simply read, “In Washington, It’s Sean Parker versus Sean Parker.”

Some have framed the Upton situation as a sign of Silicon Valley’s growing pains while it navigates the complicated world of political spending. But there’s another explanation: the tech industry is maturing. And, like any mature industry, the tech sector includes companies and individuals with multiple interests, some of which will invariably clash and find their way into the political sphere, where they’ll likely be taken in stride. Washington, like Silicon Valley, is deeply familiar with contradictions and hypocrisies.