Did the Tea Party Help or Hurt the Republicans?

Is the Tea Party responsible for yesterday’s election results?? Probably.? But perhaps not in the way you were thinking.
Journalists have written thousands of pages describing the anger, fury or excitement of the Tea Party.? But this isn’t how an economist would approach the question.? Perhaps the single deepest idea in economics is the opportunity cost principle.? And so it is worth asking: What is the opportunity cost of an active Tea Party movement?? To figure this out, you need to ask: “Or what?”
When you ask this question, you realize that figuring out the influence of the Tea Party requires comparing last night’s results to the alternative.? What election outcomes would have occurred had Tea Party activists not started getting organized a bit more than a year ago?? We don’t observe this counterfactual, but we can make some informed guesses.
My guess is that if there were no Tea Party, then the Republicans would likely have fielded more credible candidates who would have won both the Delaware and Nevada Senate races.? Likewise, a weak Tea Party candidate may also cost the Republicans the Colorado Senate seat.
There were successes for the Tea Party.? But these aren’t successes relative to the “or what?” question.? It’s likely that just about any Republican could have won in those races where the Tea Party lights shone brightest – Rand Paul‘s election to the Kentucky Senate seat, Marco Rubio defeat of Florida Governor Charlie Christ in their Senate race, or Mike Lee‘s win in Utah.
And in Alaska, voters appear likely to have done an end-run around the fervent Tea Partiers,?electing the newly-independent Lisa Murkowski.? If there were no Tea Party, she would surely be a less disaffected member of the Republican caucus.
Even if the Republicans had gotten closer to a fifty-fifty senate, they probably couldn’t have wrested control from the Democrats, because a Tea Party-laden Republican caucus is surely?less attractive to potential party-switchers like Joe Lieberman or Ben Nelson.
Now perhaps there were some congressional races where Tea Party enthusiasm carried the day.? But you’ve got to balance this against the possibility that unpopular candidates in the headline Senate and gubernatorial races actually hurt other Republicans down the ticket.
I’m not convinced by my analysis.? But I do wonder: What would this morning’s newspapers (and next year’s Congress) look like had the Tea Party movement never been launched?