After several weeks in which he vetted candidates for the vice presidency by putting them on parade at campaign rallies as if they were participants in one of his beauty pageants, Donald Trump tweeted out that he has chosen Indiana Gov. Mike Pence — a politician of hidden (and very green) assets — as his running mate.

Compared to other potential Trump picks, particularly Chris Christie and Newt Gingrich, Pence registers relatively low on the charisma and celebrity meters. But on the money-in-politics meter, Pence registers off the charts.

So, yes, there are ways in which Pence seems an unlikely political partner for the outspoken billionaire: Originally a supporter of Texas Sen. Ted Cruz’s bid for the GOP presidential nomination, Pence is a dedicated free trader who backed many of the trade deals that Trump is vowing to tear up.

But Pence could shore Trump up with Republican social conservatives: Just a few months ago, the governor signed legislation restricting abortion rights that set off an innovative protest by some women’s groups. And Pence’s only real brush with national notoriety came when he had to back down from a “religious freedom” bill that would have allowed Indiana businesses to refuse service to LGBT people after Hoosier sports and business interests blew up over the potential boycotts the state might face. As a former head of the Republican Study Committee, a subgroup of the House Republican Conference’s most conservative members, he is still enormously popular with his Capitol Hill colleagues, including some who have been less than enthusiastic about Trump.

Most importantly for Trump however, is what Pence could mean to his fundraising prospects. Over the course of his political career, which includes 10 years in Congress before becoming governor, Pence has attracted the support of conservative heavy-hitters, including some of the same wealthy ideologues who have so far been sitting on the sidelines, turned off by Trump’s questionable conservative credentials and fondness for spectacle over substance.

In particular, he is a favorite of the dark-money-churning Koch brothers, whose vast political network often plays a role in coordinating donations among other right-wing moneymen. A spokesman for the brother’s Freedom Partners’ group, the Kochs’ umbrella organization with a membership composed of hundreds of conservative millionaires and billionaires who each year pay six-figure membership dues, told The Washington Post that Pence’s addition to the ticket would not alter the group’s plan to focus its giving this year on Senate races.

Yet the ties between Pence and the politically active brothers are manifold: According to records compiled by the National Institute of Money in State Politics, David Koch has donated $300,000 to Pence over the years in his own name, and given additional donations from Koch Industries and its PAC. Mark Holden, a key operative in the Koch political apparatus, also made donations totaling $200,000 in his own name. Such direct contributions are only the tip of the iceberg when it comes to the brothers’ efforts on behalf of favorite candidates. Koch-backed outside groups such as Americans for Prosperity, which under current law are allowed to make unlimited expenditures on behalf of political candidates, and which provide the brothers’ wealthy allies with channels to make political contributions anonymously, also have backed Pence. Though such groups are legally exempt from having to make most of their expenditures public, AFP and another Koch-funded group, the Judicial Crisis Network, have been buying TV ads in Indianapolis, Federal Communications Commission records reveal.

In addition, many former Pence staffers have gone on to work for the Kochs: Marc Short, who served as chief of staff while Pence was running the House Republican Conference, moved on to a job at Freedom Partners.

Pence also has a friend in Dean White, a 93-year-old billionaire and Indiana native who made his money in billboards before moving into hotels and real estate. White has poured over $7 million into Republican politics; he’s given Pence $775,000 over the course of his career.

Another prominent Pence backer is Tony Moravec, a Columbus, Indiana, businessman who made his money in the pharmaceutical industry. Unlike White, Moravec is not a big player in Republican politics: The $431,735 he spent backing Pence for governor makes up the bulk of his political spending, according to the National Institute for Money in State Politics — though he did once spend $2 or $3 million to fix up an ice cream parlor he likes.

A number of other prominent conservative donors round out Pence’s list of backers, including the late Texas homebuilder and Swiftboat Veterans for Truth bankroller Bobby Jack Perry, charter school advocate and chemical company founder John D. Bryan, investor and anti-income tax activist Rex Sinquefield, private equity magnate John W. Childs, investor Lawrence F. DeGeorge and Papa John’s CEO John Schnatter.

Pence had already geared up to run for re-election as governor this year, and, reflecting a national trend, much of this funding has been coming from LLCs — business entities often used to hide the identities of political donors. For example, Chagrin Executive Offices LLC donated $95,000 to Pence’s re-election bid. The LLC is registered to Robert Murray, an outspoken Republican donor and head of coal company Murray Energy.