Since the beginning of the government shutdown, radical Republicans have dictated the agenda for the rest of their party, unilaterally steering their party towards a prolonged shutdown in the effort to defund Obamacare. In day six of the closure of the Federal government, the cause of this rule by minority is becoming clear: the 2010 Citizens United v. Federal Election Commission Supreme Court decision.

The case, familiar to many during the election season, not only radically altered campaign financing, but has changed how a political party decides its priorities. Instead of depending on polling of its constituency or whether a vote is better for the party as a whole, spending by the billionaire Koch brothers (unleashed by the Citizens United decision) has given Republicans two options: Vote to defund Obamacare or get primaried.

In an article in The New York Times today, the government shutdown is traced to a meeting of conservative lawmakers, along with the Koch brothers, who came up with a plan to defund Obamacare through any means necessary, including a prolonged shutdown of the Federal government.

“They’ve been hugely influential,” David Wasserman, who works for a non-profit that monitors House campaigns, told the Times. “When else in our history has a freshman member of Congress from North Carolina been able to round up a gang of 80 that’s essentially ground the government to a halt?”

Wasserman is referring to Representative Mark Meadows, who has positioned himself at the center of the fight to defund Obamacare. And while the Citizens United decision has essentially enabled minority rule, another campaign spending case was taken up by the Supreme Court this week with the chance to destroy what little campaign finance regulations remain.

McCutcheon v. Federal Election Commission, which began hearings this week, is a challenge to whether private citizens could put huge amounts of money directly into the hands of politicians. Slate explains, "Federal law currently caps at $48,600 the total amount than an individual can give to all federal candidates for office during a two-year election cycle."

If the Supreme Court decides to overturn limits on personal donations, the final barriers separating billionaires from essentially appointing the Congress (through either well-funded primaries against incumbents, or the threat of a primary) will be destroyed. While Chief Justice John Roberts will most likely be the deciding vote, his opinion on Citizens United does not bode well for supporters of campaign finance regulation. Then again, perhaps in an attempt to keep the Republican party from destroying itself through Tea Party radicalism, Roberts might vote to maintain the regulations.

Either way, the full effect of Citizens United is on display in the ongoing shutdown, rearing its head outside of an election cycle, seriously crippling the standing of the Federal government.