Like most progressives, since its inception I have been challenged to decide what to make of the tea party.

At first it seemed quixotic. As it grew and attracted 10 times its weight in media attention, it became by degrees offensive and alarming. But at the same time, I found it occasionally admirable, if only for the sake of its adherents’ spunk. Watching them on FOX, I sometimes mused what a powerhouse the Democratic party would be if we progressives had as much energy and strength of conviction.

That much said, what does a progressive make of the tea party? Is it here to stay? Will it grow? Will it become the third party both sides of bipartisanship have half expected as a just dessert for our mutual sins? Will it win elections? Could it win the White House? When all is said and done and the history books are written, will it prove to have been a good thing or a bad thing for America?

It is known by all that American democracy is an experiment. There has never been a republic quite like ours. Even the founding fathers knew their design was an act of faith based on a set of ideals. As the anecdote goes, after the Constitutional Convention a woman asked Benjamin Franklin if we were to have a republic or a monarchy. “A republic,” Franklin famously replied. “If you can keep it.”

In his latest book, “The Science of Liberty,” Timothy Ferris takes an enlarged point of view about the American experiment in democracy. He argues that the genius of our system is that we are free to perpetually try new methods, programs, ideologies, and philosophies, and that while the majority of these fail, somehow we still move forward. To demonstrate the point, Ferris describes an experiment. Ask a group of people to estimate how many marbles are in a jar. Inevitably, the numerical average of the estimates will be startlingly close to the correct number, and usually closer than the closest individual estimate.

At first this seems to make sense. Of course the average is close. But upon further reflection, one begins to wonder why the average was so close, and not, say, consistently some percentage too low or high. What unseen rule influences the experiment?

The same can be said for American democracy. Our swings to the left and to the right and every other which way all average to move us ahead. But why is it so? Is it our native good intentions? Is it something about our vast codes of law? Is it organic to this land and its expansiveness? Or is it the benign influence of the God whose name we invoke on the dollar bill?

Whatever it is, if we can have faith in anything about America, we can have faith that all of the contemporaneous ups and downs of we the people and our government tend to goodness. It remains for us only to hold fast to that faith and keep ourselves engaged and informed. Roosevelt’s socialism, Kennedy’s activism, Reagan’s deregulation, Bush’s conservatism, and Obama’s — however one characterizes what Obama does — all these are subservient to the whole. They are estimates of the number of marbles in the jar. None is as right as all averaged together.

And so we progressives may say of the tea party, it is yet another experiment. It may succeed, though history suggests it will fail. But either way, it makes its contribution to our future as it becomes part of our past.

Seeing it in this light makes a progressive like me much happier than seeing posters of Obama with a Hitler-like mustache painted on his face. That we Americans are still experimenting, and still learning, may be the one thing all sides can agree on. Let’s see how this tea-party experiment turns out. However it does, we’re sure to learn something from it.

Chris Mills lives in Groton with his wife. He has three adult children. Chris welcomes reader feedback at