Most financing for federal political campaigns comes from the top 2% of individuals and corporations and elected officials nearly always reflect those who have given them big money. Public financing would take that element out of the public process and make officials more accountable to the public at large. Maine and Arizona already have public financing and it has worked very well.
All corporate lobbying should be prohibited on a similar principle of financing by the wealthiest coroporations and industries. Politcal votes then represent those corporate interests rather than the broader public.