This is America, and this is the Supreme Court, which recently struck down a limit on spending by political parties. But will this give undue influence to corporations and special interest groups? And who will it benefit come the midterms? Since America's founding, the right to speak freely has been a cornerstone of democracy. But when speech costs money, does the loudest voice always win? The Supreme Court's latest ruling on political campaign finance removes the last major federal limit on coordinated political party spending, completing a decades-long transformation of US campaign finance. Spending in American politics has now reached billions every election cycle, with the US standing apart from most democracies. Super PACs allow billionaires to pour unlimited amounts into campaigns, and dark money groups mask the identities of their donors, preventing voters from knowing who's trying to influence them. Races for a congressional seat regularly attract tens of millions in spending....