Alaska Senate candidate Dan Sullivan's (R) family is stepping up to help his campaign, giving $300,000 to a super-PAC backing Sullivan.

Sullivan's parents and brother combined to give the money to Alaska's Energy/America's Values in July, according to recently filed campaign finance reports.

The Sullivan family, based in Ohio, runs RPM International and has been a major Republican donor for years, and is a close ally of National Republican Senatorial Committee Vice Chairman Rob PortmanRobert (Rob) Jones PortmanCommittee chairman aims for House vote on opioid bills by Memorial Day Flake to try to force vote on DACA stopgap plan Congress punts fight over Dreamers to March MORE (R-Ohio).

Democrats have sought to make hay out of Sullivan's Ohio upbringing and the outside money flooding in to help him, while Republicans have flogged the fact that the super-PAC backing Begich is mostly being funded by Senate Majority PAC, a group with close ties to Senate Majority Leader Harry ReidHarry Mason ReidWATCH: There is no Trump-Russia collusion and the media should stop pushing this The demise of debate in Congress ‘North by Northwest,’ the Carter Page remake MORE (D-Nev.).

Sullivan is the front-runner against Alaska Lt. Gov. Mead Treadwell (R) and 2010 Senate nominee Joe Miller (R) heading into next Tuesday's primary.