"It is despicable": House Democrats rage over Republican stock trading "set-up"

House Democrats went into the vote on the Stop Insider Trading Act last month groaning that it was all a big Republican set-up.

Now they're fuming that the trap has been sprung.

Why it matters: A well-funded Republican group is blanketing the airwaves lauding GOP lawmakers in key swing districts — including some with reputations for prolific stock trading — as champions on the issue.

"Corrupt congressmen treat the House floor like a trading floor.

Thankfully, Congressman Rob Bresnahan voted to stop it," says one of the ads .

Issue advocacy group Choose Freedom Inc. has put a whopping $9 million into running the spots across nearly 20 congressional districts, according to ad tracking firm AdImpact.

Catch up quick: The House voted 232 to 198 in July to pass the Stop Insider Trading Act , which would ban members of Congress and their families from purchasing individual stocks.

The bill only applies to the legislative branch, however, and has carveouts for holding onto and selling pre-owned stocks, and buying pooled investment vehicles such as mutual funds and ETFs.

The bill "allows members to still own stock and doesn't include the president or cabinet," Rep.

Debbie Dingell (D-Mich.), who chairs House Democrats' messaging and policy arm, told Axios.

House Democrats also fumed at the inclusion of an unrelated provision in the bill requiring photo ID to vote in federal elections — and in the end, only 13 of them voted for it.

What they're saying: "To call this a stock trading ban is disgraceful," Rep.

Joe Morelle (D-N.Y.), the ranking member of the House Administration Committee, said in an interview with Axios.

"I don't know how anybody would sign off on this," he said of the ad campaign.