Unlimited corporate political spending appears to be a contributing factor to why Republicans have taken control of 32 state legislatures and 33 state governorships in recent election cycles, a new analysis released this month found.

A report recently published by researchers at the University of Chicago, Columbia University and the London School of Economics and Political Science takes a deep dive into campaign finance data and uncovered a connection between the deregulation of campaign finance, corporate spending and the surge in Republican representation in state government. The authors noted:

We find that Citizens United increased the GOP’s average seat share in the state legislature by five percentage points. That is a large effect — large enough that, were it applied to the past twelve Congresses, partisan control of the House would have switched eight times. In line with a previous study, we also find that the vote share of Republican candidates increased three to four points, on average.

The report finds that in states with a strong corporate presence and low union membership, Republicans have won a disproportionate number of seats since Citizens United, the 2010 Supreme Court ruling that lifted limits on political spending from corporations and other outside entities.

Prior to the ruling in 2010, 23 states had laws that banned corporations and unions from using funds for outside political spending. As a result of the court’s decision, these states had to overturn these campaign laws.