Even leaving aside government policy, whole industries are already making expensive changes around the perceived need to 'go green.' Al Gore and countless other prophets of global catastrophe are making megamillions pushing these expensive solutions. Schoolchildren around the globe are being frightened by tales of impending calamity.
If candidates spend money on ads and other political speech and their opponents are rewarded with government handouts to attack them, that chills speech and is unconstitutional. Non-participating candidates certainly don't volunteer to allow their opponents to receive taxpayer subsidies to bash them.
Every major federal campaign-finance-reform effort since 1943 has attempted to treat corporations and unions equally. If a limit applied to corporations, it applied to unions; if unions could form PACs, corporations could too; and so on. DISCLOSE is the first major campaign-finance bill that has not taken this approach.