CHICAGO (CBS) — The prime strategy for Illinois democrats for the upcoming fall election is linking every republican to President Donald Trump.

A new ad by democratic challenger Sean Casten claims Congressman Peter Roskam and Trump are practically joined at the hip. CBS 2’s Political Reporter Derrick Blakley fact-checked those claims.

“Career politician Peter Roskam is supposed to work for us. Instead, he’s been a rubber stamp for Donald Trump,” claimed Sean Carsten.

CBS 2’s Derrick Blakely said that statement is true. According to Congressional Quarterly, Roskam voted 94% with President Trump; but Roskam called that misleading, also pointing to his disagreements with Trump.

“When Donald Trump decided he wanted to cut Great Lakes funding, we were able to roll him, get it done. He came out against sanctions for Russia for meddling in the 2016 election; but when the bill ended up on his desk, with my support, he was forced to sign it.”

Roskam’s record is rock-solid conservative, with 92% approval from manufacturers, 93% from the NRA, only 3% from conservationists, and zero from abortion advocates.

“There’s something shady about Sean Casten. Casten does one thing, but does another,” Roskam’s political ad claims, attacking Casten for taking the kind of government tax breaks at his former business that Casten otherwise said he opposes.

Casten said that charge is flatly untrue, stating, “That’s pretty rich from someone who’s taken hundreds of millions from the pharmaceutical industry and the gun lobby. If you want to see someone corrupted by money, he should look in the mirror.”

Another development in this closely-watched campaign is that Casten said a private poll taken for him shows him ahead for the first time by a margin of 47% to 44% with 9% undecided.

Nationally, democrats have targeted Roskam’s seat in their campaign to retake the House.