alt Hacker NewsThe First Amendment does not explicitly mention campaign spending (or political campaigns at all), and until 2010, the First Amendment was not considered to apply to monetary spending in political campaigns.
The right to petition the government is explicitly protected, but that doesn't apply in the case of IL-9, which was an open race and therefore none of the candidates were actually elected representatives.
Even still, this is money on how a private entity decides who its going to support for a future election.
None of these people are even running for government yet.
If the democratic party wanted to so something about it, they could, but the freedom of expression and association guarantees that a party that wants to have lots of money spent on ads an such can do it