Biden, who announced his candidacy last week, has focused on appealing to the Rust Belt workers who helped Trump win in Pennsylvania and the upper Midwest. The International Association of Firefighters endorsed him on Monday. Several polls on Tuesday showed the former vice president solidifying his lead in a crowded Democratic 2020 field.

“I’ve done more for Firefighters than this dues sucking union will ever do, and I get paid ZERO!” Trump said in one posting to his nearly 60 million followers on the social media platform.

Along with that message, Trump retweeted Fox News personality Dan Bongino, along with people who said they were firefighters or their family members about a divide that exists between union leaders and members.

Another person who identified themselves as a firefighter said they plan to vote for the incumbent.

The retweets were replies to the earlier assertion by Bongino, a former Secret Service agent and New York police officer, that the firefighters he knew weren’t lining up behind Biden.

Trump also used Twitter Wednesday to signal he overrode a decommission order for the aircraft carrier U.S.S. Harry Truman, as well as quoting Missouri Republican Senator Josh Hawley saying Democrats can’t accept there was “no collusion, there was no conspiracy, there was no obstruction.”