There’s never been anything quite like Colorado’s 2018 primary race for governor. In the end, it cost $34.7 million, with about half of the contributions coming from the candidates themselves.

Democratic nominee Jared Polis led the way, digging into his own wallet for an unprecedented $11.3 million. He spent nearly all the money on the primary. His campaign has just $228,268 left, but Polis, a multi-millionaire, can write a check to replenish his coffers overnight.

(Chart: Ben Markus/CPR News | Data: Colorado Secretary of State)

The party’s choice did receive an assist from at least two outside groups. Almost $1 million was spent on his behalf by Sierra Club’s independent expenditure committee and by Bold Colorado, an IE committee primarily funded by the Gay & Lesbian Victory Fund.

Polis and the PACs supporting him spent almost as much as all of his Democratic challengers and their PACs combined. Next closest to Polis was Democrat Mike Johnston, who spent $2.3 million, but also got a huge assist of $5.23 million from Frontier Fairness, his Super PAC. Johnston finished third in the Democratic primary voting.

Cary Kennedy and her Super PAC, Teachers for Kennedy, raised $4.2 million. The lionshare of her contributions to the PAC came from Emily’s List, which aims to elect women, and the National Education Association, the nation’s largest teachers union. Donna Lynne raised just $1.1 million, and didn’t appear to have any PAC support.

The Republican side of the primary looked inexpensive by comparison, but wealthy candidates still dipped into their own pockets. GOP nominee Walker Stapleton personally contributed about half his $2.6 million war chest. His PAC, Better Colorado Now, chipped in another $1 million on his behalf, with Extraction Oil & Gas as the largest contributor. Another large contributor was Colorado Taxpayers Advocate Fund, a 501(c)(4) that shields the identity of its funders.

In terms of dollars per vote, Stapleton got the most bang for his buck. Each vote he received cost about $16. Polis spent $44 a vote. That may indicate that the GOP race was less competitive, more than Stapleton being extremely efficient with his money.

(Chart: Ben Markus/CPR News | Data: Colorado Secretary of State)

Businessman Victor Mitchell finished a distant second to Stapleton, despite spending almost $5 million of his own money. His campaign was self-funded and he didn’t appear to have received any PAC support.

The remaining GOP challengers Doug Robinson and Greg Lopez spent $1.1 million and $42,949 respectively.