INDIANAPOLIS (AP) — Indiana Gov. Mike Pence’s campaign fundraising advantage over Democratic challenger John Gregg was fueled by $1 million from a Republican Governors Association-backed group.

State election division records show Pence’s campaign received the contribution two days before the Dec. 31 reporting deadline. That helped Pence’s campaign raise some $3.5 million during the last half of 2015, while Gregg’s campaign collected nearly $2 million.

Pence also banked sizeable checks in the last days of 2015 from several out-of-state supporters, including $100,000 from billionaire conservative activist David Koch and $10,000 from former Anheuser-Busch CEO August Busch III.

Labor unions gave more than $500,000 to Gregg. He also received $20,000 from Indiana Pacers owner Herb Simon.

The Pence campaign says it ended 2015 with nearly $6.8 million, compared to $3.5 million for Gregg.