Here's who is bankrolling the top presidential candidates

By Rick Newman and Emma Peters

Bernie Sanders is far behind Hillary Clinton in the polls, but the liberal curmudgeon is tied with Clinton in one interesting contest: the number of Google (GOOGL) employees donating to the campaign. Each candidate has received money from 26 Googlers, according to the latest federal fundraising records.

The 2016 presidential election is still 16 months away, but the fundraising push is in high gear, given that the winner may need $1 billion or more to win the White House. Candidates and groups supporting them are likely to spend the most money ever in a presidential campaign, partly because the Faustian innovation known as super PACs allows rich donors to give unlimited amounts to groups affiliated with candidates they support.

Two super PACs supporting Jeb Bush, the presumed Republican front-runner, have raised a whopping $108 million so far, according to the Bush campaign. They could pull in several multiples of that by Election Day. Super PACs supporting Hillary Clinton, Bush’s Democratic counterpart, have raised just $24 million so far, though Clinton’s campaign proper has outraised Bush's by more than 4 to 1.

Yahoo Finance is closely following the money pouring into the 2016 campaign, and we analyzed newly released data to see which companies are aligned with which candidates. (Our full methodology is at the end of this story.) Not surprisingly, Bush and Clinton are pulling down millions from deep corporate connections. But we found a few unexpected things as well. While it’s no secret that Jeb Bush is Wall Street's preferred candidate, for instance, Hillary Clinton more than makes up for that with thousands of donations from attorneys at powerful law firms.

Many analysts consider ultraconservative Sen. Ted Cruz of Texas a fringe candidate, yet his campaign ranked second in the amount of money raised through the first half of 2015. And the iconoclastic Sanders—a self-described socialist—has a respectable amount of support from pockets of corporate America, with donations coming from employees of Google, Microsoft (MSFT), Wells Fargo (WFC), United Airlines (UAL) and other firms.

We researched the top sources of money for the 7 candidates whose campaigns raised more than $5 million during the first six months of the year. Donor records list contributions by individual, not by company. But they require contributors to declare their employer, if they have one, which allowed us to see which organizations have the most employees donating to a particular candidate. Here's what we found:

Hillary Clinton (Democrat). Total raised: $47.5 million. Jeb Bush has the richest super PAC, but Clinton grabbed far more cash from donors giving directly to a campaign. Law firms were Clinton’s biggest donors. Florida-based litigation firm Morgan & Morgan had the most givers, with 155 different attorneys and other employees donating to Clinton. Powerhouse firms Debevoise & Plimpton and Akin, Gump, Strauss, Hauer & Feld came next, with 49 and 48 donors, respectively. Clinton’s fourth-biggest source of funds was L.A. talent firm Creative Artists Agency, with 47 donors—indicating her strong foothold in Hollywood. Rounding out the top 5: Morgan Stanley (MS), with 44 employees giving to Clinton’s campaign.

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Ted Cruz (Republican), $14.1 million. Cruz’s biggest source of funds so far is Texas-based Woodforest National Bank, whose CEO, Robert Marling, is a big Republican donor and Cruz backer. Other firms with employees donating to Cruz include mining firm Jennmar and the U.S. Postal Service. One surprise in Cruz’s records is the light showing by Goldman Sachs (GS), which only had three employees who donated to Cruz. The candidate’s wife, Heidi, is a high-ranking Goldman exec on unpaid leave for the duration of Cruz's campaign, which was expected to draw a meaty chunk of Goldman money but so far hasn’t.

Bernie Sanders (Democrat), $13.7 million. The left coast likes the leftist Sanders, with Google (26 donors) and Microsoft (15 donors) being his top sources of corporate money. Wells Fargo and United Airlines each had 8 workers donating to Sanders, while Princeton University had 5.

Jeb Bush (Republican), $11.4 million. Bush ranked fourth in money donated directly to the campaign, but he didn’t declare his candidacy until mid-June, so his $11.4 million haul represented only about two weeks of fundraising. Bush’s biggest source of funds is Wall Street bank Goldman Sachs, with 55 donors, followed by investing firm Neuberger Berman, with 23 donors. Tenet Healthcare (THC)—where Bush was a director from 2007 through 2014—is Bush’s third-biggest source of money, with 13 donors.

Ben Carson (Republican), $10.6 million. Carson raised a respectable amount of money, but his records show no connection with any particular firm; no company accounted for more than 5 donors. That could make Carson a true man of the people who's raising funds on personal appeal alone, rather than any corporate connections.

Marco Rubio (Republican), $9.8 million. The Florida senator boasts one enviable source of funds: Goldman Sachs, with 27 donors. After that, however, Rubio’s corporate fundraising drops off, with the next biggest contributor—Bank of America Merrill Lynch (BAC)—accounting for just 7 donors.

Rand Paul (Republican), $5.3 million. The top donor group for libertarian Paul was the U.S. Air Force, with 10 contributors. That probably reflects connections made through Paul’s father Ron—the former Congressman and presidential candidate—who was a USAF flight surgeon early in his career. Paul’s next biggest sources of donors: IBM (IBM), Wells Fargo and Microsoft.

Methodology: We analyzed federal records made public July 15 on donations by individuals to presidential campaign committees. These records do not include donations to super PACs or other outside groups, which are due to be made public July 31. While donors are required to list their employer, the donations we counted were made by individuals, not by companies. We sorted the data in a way that allowed us to count the number of donors for each employer listed. We excluded records in which an employer couldn't be ascertained. Since donations are year-to-date through June 30, candidates who declared their candidacy after that date, such as Scott Walker, aren’t included. We limited our analysis to candidates who raised $5 million or more, resulting in the list of seven candidates above. Unlike donations to super PACs, which have no limit, donations to presidential campaigns are capped at a maximum of $5,400, which makes it important for candidates to solicit money from as many people as possible.

Rick Newman’s latest book is Liberty for All: A Manifesto for Reclaiming Financial and Political Freedom. Follow him on Twitter: @rickjnewman.