From time to time I enjoy pondering counterfactual history questions like “Should the Republicans have nominated Romney in 2008?” or “Could Clinton or Edwards have beaten Obama in Iowa?”

Since establishment Republicans suffered shocking losses last month in the Delaware and Alaska U.S. Senate primaries, another question has been on my mind. Could a primary challenger have taken out or seriously threatened Senator Chuck Grassley in Iowa?

In July 2009, when Grassley was pretending to seek a compromise on health care reform, State Representative Kent Sorenson made a splash in the Iowa rightosphere with an open letter scolding Grassley for not being conservative enough. (More than a year later, Sorenson’s letter is still the second most-viewed post ever at The Iowa Republican blog.) Some Iowa wingnuts grumbled about a possible primary challenge to the five-term incumbent. At the time I dismissed the speculation:

Social conservatives are likely to focus on the governor’s race between now and June 2010. Bob Vander Plaats will officially announce his candidacy on Labor Day and will need all the help he can get from the religious right if former Governor Terry Branstad gets back into politics. […]

Some Iowa legislative districts may also be targeted by social conservatives, if there is an open GOP primary or a Republican incumbent deemed to be doing too little to advance the religious right’s causes. The Iowa GOP is in a bit of a bind; party strategists understand that they should emphasize economic issues, but some social conservatives become angry when Republicans say too little about abortion or same-sex marriage. We saw this dynamic play out in the recent House district 90 special election. Although Republican candidate Stephen Burgmeier toed the line on the so-called “pro-family” agenda, two conservatives ran against him because he wasn’t emphasizing their issues. The two minor candidates received 282 votes combined, while Burgmeier lost to Democrat Curt Hanson by 107 votes.

You can run a statehouse campaign on a shoestring, while taking on Grassley in a GOP primary would be a very expensive hopeless cause. The religious right may give other establishment Republicans headaches next year, but Grassley is home free.

Perhaps I was too quick to assume a primary challenge against Grassley would have been a “hopeless cause.” No one expected Mike Castle, winner of many statewide elections in Delaware, to have any trouble dispatching Christine O’Donnell. Same goes for Joe Miller’s upset win over Lisa Murkowski in Alaska.

I still think activist energy couldn’t have realistically been divided between two statewide Republican primary races. Most of Iowa’s “tea party” types backed Vander Plaats for governor, and it’s hard for me to see how a challenge to Grassley could have gained steam. Grassley didn’t always thrill the wingnut set, but Branstad’s record of raising taxes, expanding state government and choosing a pro-choice running mate enraged them and provided better fodder for a primary challenge.

Had Republican power-brokers failed to talk Branstad into returning to politics, a serious challenger to Grassley might well have emerged.  Vander Plaats would have been in a commanding position to win the GOP nomination for governor. After spending more than $2 million, former four-term Governor Branstad only beat Vander Plaats by 50 percent to 41 percent in the primary. I can’t see how a lesser-known candidate like Christian Fong could have beaten Vander Plaats.

Without Branstad to fight, tea party and/or social conservative activists might have redirected their energy against Grassley. Remember, a sizable number of GOP state convention delegates were able to deny the senior senator a voting delegate slot at the 2008 Republican National Convention. They had plenty to be mad about even after he turned wholeheartedly against “Obamacare,” denouncing as unconstitutional the individual health insurance mandate he once supported. A challenger from the right could have complained about Grassley’s votes on immigration policy and his role in passing the bill that expanded Medicare. They could have mobilized against his questioning the tax-exempt status of some televangelists (even though that line of inquiry never produced any results, as far as I know).

Although a governor’s race without Branstad might have produced a spirited Senate primary, I believe Grassley would have survived, for one big reason: the Iowa caucuses.

Heroes of the far right, most notably Sarah Palin, played a big role in this year’s GOP primary upsets. But it’s telling that Palin endorsed Branstad in the Iowa governor’s race. She gave no reason for backing a candidate with such a “big government” background. In New Hampshire’s U.S. Senate primary, Palin also endorsed the “establishment” candidate, state Attorney General Kelly Ayotte, rather than the more conservative Ovide Lamontagne.

It’s not hard to see what separates Iowa and New Hampshire from states where Palin and others have pushed for uncompromisingly right-wing candidates.

In the Iowa governor’s race, I kept waiting for out-of-state groups and opinion leaders to get behind Vander Plaats the way they embraced Marco Rubio in the Florida Senate primary, but it never happened. Mike Huckabee was one of very few nationally known figures to back Vander Plaats, and that was a special case, since Vander Plaats chaired Huckabee’s Iowa campaign in the last election cycle.

If conservatives with ambitions to play a significant role in the next presidential race (either as a candidate or as a kingmaker) were reluctant to take on Branstad, I doubt they would have gotten behind a primary challenge to Grassley. Taking on Mike Castle or Lisa Murkoswki is different from taking on an institution in an early nominating state.

What do you think, Bleeding Heartland readers?