OK, since you're genuinely asking, here's how this goes.
There are like 10 different things going on, but the most important thing is that the US allows for a certain amount of equity or stock in a company to be held without disclosure, i.e. anonymously. This is typically done with beneficiary ownership, i.e. if you buy Tesla stock today, you will not appear in the stock registry but your bank or broker does - they hold the stock in your name. This works up to a point, I believe it's 9% of outstanding shares or 10% of equity in the USA, by which point the ultimate holder must be registered and is subject to a bunch of additional KYC type investigation. So one of the most important ways in which pumping the valuation of a company is very important for lobbying efforts, is to allow that anonymous portion of an investment to be made as large as possible. With a 100B valuation, xAI would be able to accept - essentially - political donations up to $9B anonymously, while a more realistic $100M valuation would allow only $9M.
Additionally, these types of transactions happen through shell entities. It's not quite true that you're anonymous when you buy shares or equity in xAI of less than 9% - a lot of transaction information including the transaction entity is still required to be registered. I don't know exactly what it's called in the US, but in Europe this is called a UBO declaration (ultimate beneficial owner declaration). The trick here is to put this equity into a shell company (a company that only exists to own this particular bit of equity) and maybe shell that a couple more times, every time registering that shell entity in a country that benefits you in some kind of way. For instance, one shell entity has no extradition treaty with the US, another is allowed to withhold the names of investors, another again is not required to pay any taxes on capital gains. With traditional manipulative foreign actors (and yes, this has existed for hundreds of years now), each individual contribution is so small as to make it impractical to set up like a million different shell entities to be able to donate a couple billion. By increasing the investment amounts, this whole game becomes way easier.
It's a bit depressing to view the world this way, but consider every large foreign investment as a bribe of about 10% of the valuation of a company. So with xAI now worth 80B on paper, this means the Saudis have just bought Elon and Trump for about $8B. Plus whatever else they pumped into a bunch of other companies through that same mechanism.