Some home truths from the old Business prof. A business gets paid to provide goods, services or for the use of something they own. They don't get paid for doing or providing nothing.
Joe Biden is, by the standards of everyday Americans, wealthy. As a Senator, Vice President, and President he has been paid well, but not enough to live as he has lived, and accumulate the property and assets he has accumulated. And he didn't inherit vast wealth.
The foreign firms which paid the Biden family millions - Joe, son Hunter, brother James and other family members - were paying for something. It wasn't for goods as they've produced no significant material goods to sell or rent. Thus it was for services rendered.
The only service any of them were qualified to render was influence with the US government, delivered by Senator/VP Joe. Bagman Hunter's expertise seems limited to scoring drugs, finding sex partners, and producing bad paintings. We know less about other family members but none seems to be particularly credentialed or skilled.
Those foreign entities which "invested" with the Bidens, or paid them a "salary," were buying influence and apparently believed they were getting their money's worth. Ergo, the Bidens were selling influence.
My understanding is that doing so was and is unlawful. The foregoing isn't rocket science. That no one takes action is just wrong ... it's dereliction of prosecutorial duty.
