Like most conspiracy theories, there is a fact pattern that makes this one convincing to those who want to believe: Republicans are a lot less fiscally conservative when they are in power than when they are out of power. Former Presidents Donald Trump and George W. Bush were not frugal with our money, and neither is the average Republican governor.

But we can explain this phenomenon without positing that the GOP worships at secret shrines to John Maynard Keynes.

Republican governors and presidents, like Democratic governors and presidents, know they can win political favor by handing out tons of free money.

Everyone loves Santa Claus, so when Republicans get a seat in the big chair, they hand out goodies with the same Christmas spirit as the guys ideologically dedicated to big government.

Now, after the bipartisan COVID spending spree, there’s some empirical proof that federal spending benefits incumbents politically.

“Federal pandemic aid strongly predicts incumbent performance in the 2020, 2021, and 2022 elections,” economists Jeffrey Clemens, Julia Payson, and Stan Veuger report. That is, giving out other people’s money is good for politicians.

Recall the massive federal spending spree in 2020 and 2021 in which Uncle Sam handed nearly a trillion dollars to state governments. At first, economists and lawmakers thought this money was needed to save state budgets. Soon, we learned that states were actually in great fiscal shape, but those state governments sure did love having extra money to spend.

This money was not allocated according to pandemic severity or economic distress. Nor was it allocated strictly according to population — some states got a lot more per capita than other states.

Here’s where the research of these economists comes in. Clemens and Veuger found in an earlier study just how politics determined the allocation of federal money: The most overrepresented states in Washington, those with more representation per capita in the House and Senate, got more COVID money per capita.

Starting with that insight, the economists asked just how this money affected incumbents’ reelection chances. They found that the statewide officials who did better in their reelection bids were those whose state received disproportionate COVID money.

This isn’t surprising when you think about it. Governors with bigger pots of money had more money to dole out. They could use that money to improve buildings, build new institutions, hire people, and fund schools — then appear at the ribbon-cutting and take credit. Their challengers, not being incumbents, couldn’t do that.

Federal spending, in other words, magnifies the incumbent advantage and gives incumbents a few points on Election Day.

We can see this in action. Consider the Associated Press article that ran the first week of school in 2022. “Gov. Tony Evers is giving Wisconsin K-12 public schools $90 million more in federal COVID-19 relief money, a move he announced Tuesday just before schools were to open for the fall. … The money is on top of $110 million in federal pandemic relief funds that Evers gave to schools in 2021.”

What sort of politician wouldn’t love that sort of headline? It was expensive for the taxpayer but invaluable for Evers, who narrowly won reelection in 2022.

The least cynical interpretation of all this is that federal money helps governors help their constituents, and helped constituents reward the incumbents. The economists in this study suggest that, in fact, the states with disproportionate federal COVID aid saw better outcomes.

But there’s just as much evidence for a more cynical interpretation: It’s mostly the insiders who benefit from federal largesse, while the common good isn’t served.

Places that get more federal dollars because of politics generally suffer economically because of it, one study from the pre-Tea Party era of earmarks found. How could that be? Federal money can induce companies and nonprofit groups to dial back their own spending.

“In the year that follows a congressman’s ascendancy” to a chairmanship, the 2010 study found, “the average firm in his state cuts back capital expenditures by roughly 15%. … We also find some evidence that firms scale back their employment, and experience a decline in sales growth.” An earlier study found that districts whose congressmen were appropriators saw bigger downturns in charitable activity.

Government dollars, then, don’t necessarily enrich a place because they displace private dollars. Certainly, the COVID dollars caused inflation, thus offsetting any wealth gains the extra money would have provided. But shifting the power of spending and investing from charities and businesses to the government is good for the governing class.

So, if you wonder why Republicans, who should know the harm of overspending, nevertheless spend too much when in power, here’s the simplest explanation: Even if they value fiscal discipline, they value reelection even more.