Social media mogul and SpaceX founder Elon Musk made headlines this week when he hit the campaign trail in support of former President Donald Trump.

While some on the left have mocked Musk's efforts, Pennsylvania Sen. John Fetterman recently told his fellow Democrats to be wary. 

Democratic senator says "Musk is a concern"

Fetterman issued that warning this past weekend during an interview with the New York Post, stating, "Musk is a concern."

"Not even just that he has endorsed [Trump], but the fact that now he’s becoming an active participant and showing up and doing rallies and things like that," the Pennsylvania lawmaker continued.

Fetterman likened the X owner to a superhero, saying, "I mean, [Musk] is incredibly successful, and, you know, I think some people would see him as, like, a Tony Stark."

"Democrats, you know, kind of make light of it, or they make fun of him jumping up and down and things like that. And I would just say that they are doing that at our peril," the senator added.

Fetterman: "Pennsylvania picks the president"

Musk has been active in Pennsylvania, contributing to what Fetterman believes will be a "ridiculously close" election there next month.

"Trump has a connection that's undeniable," he acknowledged. "And anyone that spends any time across Pennsylvania can see that kind of devotion and that’s why it’s going to be very close."

Fetterman sounds the alarm after Elon Musk endorses Trump, joins ex-prez for rallies: ‘A concern’ https://t.co/uaHwFqzktn pic.twitter.com/iOnYsDmyOZ

— New York Post (@nypost) October 19, 2024

What's more, Fetterman highlighted the crucial role that his home state and its 19 Electoral College votes will play, declaring, "Pennsylvania picks the president."

Pennsylvania governor: "Law enforcement could take a look at" Musk's actions

Meanwhile, Musk is facing criticism from Pennsylvania Democratic Gov. Josh Shapiro over his practice of randomly awarding a million dollars each day to someone who signed his pro-Trump petition.

According to Fox Business, Shapiro told NBC's "Meet the Press," on Sunday that "when you start flowing this kind of money into politics, I think it raises serious questions that folks may want to take a look at."

Although Shapiro stopped short of calling Musk's behavior illegal, he did say that "law enforcement could take a look at" it.

Fox News reported that for his part, Musk responded with an X post in which he said that it is Shapiro's comments which are "concerning."