“I am not a member of any organized political party,” American humorist Will Rogers once said. “I am a Democrat.”

That’s one of Rogers’ most famous quotations, and it is as true now as it was when he said it. It’s one of the reasons Democrats have had such trouble creating a coherent message to counteract the “less government” message Republicans have been preaching so successfully since the Reagan years.

Republicans have a different problem – they are too organized, as Rogers pointed out. He also once said, “Democrats never agree on anything. That’s why they’re Democrats. If they agreed with each other, they would be Republicans.”

Now more than ever in my lifetime, Republicans demand almost lockstep conformity on just about every issue – as Newt Gingrich is finding out.

Gingrich, the party’s leader during the mid-90s, is trying to revive his political career with a presidential bid that is going nowhere. On Sunday, he criticized Wisconsin Rep. Paul Ryan’s Medicare plan as “radical” and “right-wing social engineering.”

I don’t know about “right-wing social engineering,” but Ryan’s plan is pretty radical. He wants to replace Medicare as it now exists with a voucher program that gives senior citizens $15,000 a year to buy their own health insurance. It certainly deserves a healthy debate – both within the Republican Party and outside it. In fact, a healthy debate would actually help its cause. A new poll shows most voters oppose any cuts at all to Medicare, which shows how little they understand the budget realities the country faces. A healthy debate might educate them on those realities.

But Republicans are cutting Gingrich off at the knees, and, regrettably, he has already backtracked.

Republicans have always talked about being a “big tent party.” If Newt Gingrich isn’t welcome inside, that’s a pretty small tent.

Here’s the poll I mentioned.