Michael Koplow diagnoses the political situation in Tunisia, and counters the idea that Salafists could or should be excluded from the country's fragile democracy:

Democracy does not just emerge from the mist, and leaders in a newly post-authoritarian state cannot just close their eyes and tap their heels together and create a democratic political system. Democracy has been aptly described as a second-best solution, because it results from a stalemate in which no side has the power to fully impose its will and thus everyone becomes willing to roll the dice and take their chances with democratic politics in order to win something. Essentially, democracy is installed by non-democrats who have no other choice, and over time democratic politics become habituated and the system (hopefully) becomes self-perpetuating. If this does not describe what is going on in Tunisia, then I don’t know what does.

Tunisia is not filled with committed democrats, but is instead a combustible mix of parties that would all like to impose their will. The Salafists would like to create a pure Islamic state, Ennahda likely wants something closer to what the Muslim Brotherhood wants in Egypt, and the secularists want Ben Ali’s Tunisia without Ben Ali. Make no mistake though; the secular parties would just as soon impose their vision of society on everyone as the Salafists would if they had the strength to do so. The fact that none of these factions are able to carry out their will unimpeded is what gives me hope that Tunisia will emerge democratic.