When business people take out their checkbooks, they expect a good return on investment.

So Republican donors on Wall Street, many of whom bankrolled a losing Mitt Romney in 2012, were alarmed as they watched Sen. Ted Cruz (R-Texas) and Tea Party conservatives shut down the government and nearly cause a historic default — all for the sake of delaying or defunding a law, ObamaCare, that even moderate Republicans said couldn't be undone.

This take-no-prisoners approach has a broad swathe of mainstream Republican donors worried, reported Politico's Maggie Haberman and Anna Palmer:

Donors and business leaders, whose words used to carry great weight with candidates ever worried that the money spigot might be turned off, now face a new reality. It’s a Frankenstein syndrome of sorts, in which the candidates they’ve helped fund, directly or indirectly, don’t fear them, and don’t think they need them. [Politico]

In this new world, Cruz and the groups that fund him, like the Freedom Works and the Senate Conservatives Fund, are the ones benefiting from the conservative base's fervor. Last quarter, the Texas senator raised almost double what he did the quarter before, giving him an $800,000 reason to continue his aggressive approach to opposing ObamaCare.

Meanwhile, the donors who might actually fund mainstream candidates are thinking about keeping their checkbooks closed. Politico talked to Fred Zeidman, who helped fund Romney and former President George W. Bush, who wonders why he should "fuel a fire that’s going to consume us" by giving money to the GOP.

A Republican who works closely with Wall Street donors told Politico that financial types are "people who make a living analyzing risk" and want to be certain when the "government will open" and the "debt limit will be responsibly raised" before fully backing Republican candidates. And New York-based fundraiser Paul Singer is toying with creating a new organization that would only fund mainstream candidates, mostly because he is tired of the "GOP at large losing race after race."

Overall, there are signs that wealthy Republicans are moving away from donating to organizations that broadly support the GOP.

"The fact is, donors have had it," Bobbie Kilberg, a Republican fundraiser from Virginia, told the Washington Post. "I will only give to individual candidates who get it."

Of course, there is the possibility that all of this grumbling is just for show, considering that Republican donors aren't likely to switch parties, wrote The Daily Beast's David Freedlander when the shutdown started:

To be clear, none are considering joining the Democrats, and they find plenty of fault with President Obama and Senate Majority Leader Harry Reid. The deficit, taxes, and regulation remain top concerns. But several top GOP donors say figuring out a way to "break the fever" — as Obama once put it — or at least keep their fellow party members from damaging the economy any further has become Topic A in their social set. [Daily Beast]

They will have to figure it out soon. A recent PPP poll shows that the government shutdown has hurt the GOP with voters in key Senate races. Paired with the fact that, according to USA Today, many Democratic Senate candidates are enjoying an edge in fundraising, the chances aren't looking good that Republicans will take the Senate in 2014.

The picture could look the same in 2016 if Cruz, instead of a candidate with mainstream appeal like New Jersey Gov. Chris Christie, is matched up against presidential favorite Hillary Clinton. That could leave moderate Republican donors, once again, on the outside looking in.