For 501(c)(3)s, it is. In exchange for tax-exempt status, a group loses certain options.
But the DOJ wouldn't touch those charges though as they're civil (IRS under Treasury) and the criminal charges could be fatal to the org by themselves.
Though, regardless of the criminal outcome, if the facts in the indictment are proven, I'd wager the IRS' case is proven implicitly which could also be fatal.
No it isn't. A 501c3 can't participate directly in a campaign. That's it, that's the whole rule. Plenty of 501c3's are nakedly and openly partisan. Center For American Progress is a c3. Heritage is a c3. AEI is a c3. Claremont is a c3.
Again, I encourage you to read Patrick's post, specifically the section titled "July 2021: The CTT coalition attempts non-partisan interdiction of Trump PAC fundraising" where it describes their direct involvement against a single, specific candidate's PAC.
You could make the claim "well, technically he wasn't a candidate at that time" but considering the PAC was a registered FEC entity raising money for campaign rallies, that argument is weak at best and absurd in reality.
But the DOJ wouldn't touch those charges though as they're civil (IRS under Treasury) and the criminal charges could be fatal to the org by themselves.
Though, regardless of the criminal outcome, if the facts in the indictment are proven, I'd wager the IRS' case is proven implicitly which could also be fatal.