A Democratic super PAC is meddling in West Virginia's Republican Senate primary to boost Don Blankenship, an energy executive convicted of conspiracy to violate mine safety standards who is viewed as the weakest challenger to incumbent Sen. Joe Manchin, D-W.Va.

Duty and Country has filed independent expenditure reports with the Federal Election Commission for hundreds of thousands of dollars in advertising opposing Rep. Evan Jenkins and state Attorney General Patrick Morrisey. The two Republicans are considered tougher for Manchin to beat in November than Blankenship, who went to prison in 2016 after being found negligent in the deaths of 29 coal miners.

Booth Goodwin is Duty and Country's treasurer. He ran for the Democratic nomination for governor in 2016. Six years prior, Manchin, then the governor, appointed his cousin, Carte Goodwin, to serve as a placeholder successor to Sen. Robert Byrd, D-W.Va., after he died in office. Manchin ran for and won the seat later that year.

Duty and Country has reported spending nearly $460,000 against Jenkins and around $30,000 against Morrisey. The super PAC's vendors include prominent Democratic firms based in Washington: SKDKnickerbocker, Moore Campaigns and Waterfront Strategies. As Democrats did in Alabama in a special election for Senate last year, they're obscuring their activity in this race by running it through a generically named super PAC rather than an official party organ or aligned political organization.

The Republican establishment is using a similar approach in the West Virginia Senate primary, but in its case, to defeat Blankenship in the May 8 primary. The nondescript Mountain Families PAC has been hammering the populist coal baron with opposition advertising, worried that he cannot beat Manchin despite how vulnerable the Democrat is in a state that voted overwhelmingly for President Trump in 2016.

CORRECTION: This story originally misidentified Blankenship as a convicted felon. It has been updated to accurately describe his criminal conviction.