One of the most familiar lines in politics comes from the 19th century English historian Lord Acton, who said, “Power tends to corrupt, and absolute power corrupts absolutely.”

People forget the last part of that quotation — “Great men are almost always bad men” — but maybe we’re seeing a rush of politicians trying to prove their greatness. That would require thought, though, and the evidence indicates that corruption is far more common than thinking.

So let’s give it some thought: What is the source of corruption?

It’s common to hear sermons on money being the root of all political evil from people as different as Hillary Clinton, who has been a nonstop fundraising machine for decades; Bernie Sanders, who has raised $140 million for his presidential run; and Donald Trump, a billionaire who could open his checkbook any time the media stopped giving him free publicity.

People love to pile on the Supreme Court’s Citizens United ruling, which, putting the principle of political free speech above practical consequences, found that the government may not limit the ability to spend money to share a political message. Free speech isn’t free, and barring spending restrains the freedom of speech.

Unlimited spending on unlimited political speech (vital in a free society) creates an unlimited freedom, as well as an annoying increase in political ads. But it doesn’t create corruption.

The money pouring into the system is just a tool that can be used for good (say, in making the case against House Bill 757, the Free Exercise Protection Act) or bad (in lobbying against S.B. 327, Georgia’s anti-BDS legislation).

If you’re clean, if you’re a politician who votes and acts based on certain core principles, all the money in the system won’t corrupt you. But if you can be bought, you’ll be bought, regardless of the amount available and whether the money moves above or below the table.

Sanders’ own success at raising money and sticking to his anti-Wall Street guns argue against his message: The system he bashes as evil neither silences him nor slows him down.

So maybe it’s not the money but the power in the system that causes the corruption, as Lord Acton argued. The closer we get to absolute power, the closer we get to certain corruption.

We don’t have to look beyond the Georgia Capitol to see how that corruption spreads and expresses itself not as avarice, but as arrogance.

In the old days, Georgia was effectively a one-party state. Democrats ruled, and Georgia long suffered through systemic intolerance and legal discrimination. Only outside intervention forced the state to change.

Now the Georgia General Assembly is predominantly Republican, and we’re in our fourth consecutive four-year term with a Republican governor. We have Republicans as lieutenant governor, attorney general, secretary of state, insurance commissioner and both U.S. senators.

Perhaps it’s just a coincidence that the return of one-party dominance has brought a return of arrogant efforts to enact legal intolerance and discrimination, this time against LGBT people instead of blacks. But maybe one party winning too easily too often leads to corruption that eats away at the principle of liberty, to be replaced by the exercise of raw power.

Only outside intervention reins in that arrogance, but the more criticism they face, the more determined certain legislators are to prove they can do what they want. I’m not sure how else to make sense of this never-ending drive for religious liberty legislation that addresses no actual problem and risks real financial and moral consequences.