Popular Congressman Justin Amash, R-Mich., is fighting back against his primary challenger Brian Ellis with a Star Wars-themed campaign event titled “The Establishment Strikes Back: Join the Rebel Alliance.”

Amash, the two-term libertarian congressman who introduced the Amash Amendment to rein in the National Security Agency spy programs, will hold a “money bomb” event Dec. 16 to raise money for the congressman’s re-election campaign.

Amash’s campaign had $164,000 cash on hand at the end of July, while his opponent has the ability to self-fund and is backed by Big Business.

“The good news is that [Ellis] doesn't have grassroots support, so he'll have trouble selling voters on his distortions and lies,” Amash's campaign wrote on the Facebook page advertising the event. “The bad news is that he doesn't think he needs grassroots support to run a campaign. He thinks he can get away with just writing checks to himself.”

Ellis has the backing of well-funded Michigan donors who have signaled their intent to replace Amash with a more establishment GOP candidate.

Amash, meanwhile, was endorsed by the National Federation of Independent Business, several small-business political action committees and the Council for Citizens Against Government Waste. He also has been backed in the past by the Detroit News and the Grand Rapids Press.

Ellis claimed Amash “turned his back on our conservative principles” by voting against the Paul Ryan budget. Amash, who explains all his votes on his Facebook page, said he voted against the Ryan budget because it didn’t balance the budget until 2024, included $600 billion in new taxes and increased government spending by 3.4 percent each year.

“On Monday, December 16, let's show the Establishment that their attempts to strike back against Congress's strongest champion of liberty will be in vain and help Justin's campaign with a huge money bomb,” the Amash campaign said.