Big Democratic donors are going to bat for Sen. Joe Manchin’s endangered re-election campaign, using a new political nonprofit to carpet bomb West Virginia with television advertising.

Duty and Honor, a 501(c)4, has invested nearly $500,000 so far to support the vulnerable incumbent in a state that is overwhelmingly supportive of President Trump, according to a Federal Election Commission filing. Political nonprofits can raise money in unlimited amounts, and do not have to publicly disclose their donors.