Dear Dr. Democrat:

The Republican Tea Party scares me. I worry that the Democrats won’t be energized enough to re-elect Obama. Could there be a third way? I’ve heard of this group, Americans Elect, that’s trying to nominate a centrist candidate over the Internet. Do you think that’s possible?

— Worried in Weehawken

Dear Worried:

Movements like Americans Elect are just sad. These people have to know that our system has calcified in a way that prevents the birth of “third parties” — even the fact that we call them “third parties” out of habit is an indicator of this. A healthy political system could sustain multiple parties, not just two or three.

There are only two known ways a new national party can form and become powerful enough to win the presidency: 1) Replace an existing party, as happened in the 1850s when the Republicans replaced the Whigs, or 2) rise up like a brush fire out in the districts, a real grass-roots movement (to mix metaphors, sort of) that starts in local elections, rises up through the state legislatures, governorships and then into Congress. That’s a generational project that has never actually happened before.

Americans Elect and their ilk are seeking a messiah, a post-partisan George Washington, Abraham Lincoln and Jesus all rolled into one who is capable of leading us into a promised land of world peace bipartisanship, where the parties govern without all this rancor and bickering. (This has also never actually happened before.)

But we’ve seen two examples of what happens when post-partisan pols get elected governor — Jesse Ventura and Arnold Schwarzenegger. Both of those guys were elected by the independent voters in their states. But within months after being elected, both found themselves alternately stonewalled and steamrolled by the partisans in their legislatures. Why? Because neither of them had allies in the legislatures whose political fates were tied to the governors’ success.

The same dynamic would occur with a post-partisan president and two-party Congress, only on steroids. Yes, it would finally bring Republicans and Democrats together, but only in that they would form ad hoc coalitions to oppose the no-party president. We’d end up with even more gridlock and even more triangulation, and a president who would find himself or herself increasingly marginalized by Congress — a lame duck before the first term was half done.

The real problem with our politics today is that the “old” Republican Party should have died in the 1960s. It did die, in a sense, and was replaced, with a big assist by Richard Nixon, by the old Dixiecrat Party — Southern conservatives for whom the main issue is white supremacy. Under Nixon, the Dixiecrats just rebranded themselves as Republicans. They did not change their views or policy positions. In fact, the party of Teddy Roosevelt and Lincoln simply adopted their white supremacist goals and objectives. It was a seamless, almost invisible transformation.

What led to this was a shift to the left by the Democratic Party, starting in the North and then culminating under FDR, Truman and JFK and, finally a Southerner, LBJ. The Southern Democrats hated this leftward shift, especially on race, which led to the formation of the Dixiecrats under Strom Thurmond in 1948. But “Dixiecrat” was never going to work as a national brand. It would be hard over time to build a base of Dixiecrats, even among true believers, in Idaho, Maine and Oregon, for example.

Nixon was motivated to bring Southern racists into the GOP because of the numbers. Republican voter registration was on a glide path to Whig-like obscurity. By welcoming in the Dixiecrats, he replenished the voter rolls with new blood.

Imagine the alternative: If Republicans had chosen not to allow the former Dixiecrats in, the white supremacist conservatives would have coalesced around George Wallace’s American Independent Party or some other innocuous-sounding brand. The AIP would have eventually come to control a bunch of state legislatures in the South, followed by governorships and then, who knows, with votes from a coalition with the more moderate GOP, the presidency.

But, in 1974, just two or three years after bringing the Dixiecrats in, Nixon resigned in order to avoid impeachment over his role in Watergate. By all rights he should have gone to prison. If he had, that likely would have been it for the GOP brand.

That didn’t happen, but it did lead to an insurgent outsider in the Democratic Party winning the presidency in the next election. Jimmy Carter is the closest we’ve come to having the sort of post-partisan president the moderate middle yearns for. He did not come up out of the national party apparatus — in fact, they hated him, as we saw when they ran Teddy Kennedy against him in 1980. He had never served in Congress and so had no strong allies or constituents there.

He was a brilliant, principled man with strong, beneficent moral convictions. But he did not go to Washington to play politics, and so he was voted out and replaced with evil incarnate.

Ronald Reagan re-energized the Dixiecrat wing of his party, starting by symbolically holding his first campaign event in Philadelphia, Miss., a random-seeming choice, except that it was the site of the murder of three Civil Rights workers in the early 1960s.

But he also courted a new configuration of the old Dixiecrats, who, in the wake of Nixon’s corruption, were calling themselves the Moral Majority — a take on Spiro Agnew’s reference to the Silent Majority of Americans who supposedly supported the war in Vietnam.

My assessment is that all of these groups: the old Southern Democrats, Dixiecrats, Moral Majority, Christian Coalition, Bush’s base and now the tea party are the same racist 20 percent of the country, who have tried repeatedly to foist their retrograde views onto the nation as a whole. What makes them so successful today is that they are bankrolled with unlimited funding by corporatist oligarchs like the Koch brothers and Rupert Murdoch.

If our system weren’t calcified into this two-party system, the old Dixiecrats would have spun off into the AIP or similar to become a permanent minority, extreme-right party, which would have let the Republicans follow their natural course and become a permanent-minority radical centrist — fiscally conservative, socially moderate — party, which is what folks like Americans Elect want today.

That would have set up an actual third-party system in which the minority centrist GOP would be forced to form coalitions with either the majority Democratic Party or the minority AIP in order to succeed in passing laws and winning the White House.

Because of the Republicans’ zombie-like determination not to die, what we’re left with is the statistically tiny tea party in nominal control of the institutional Republican Party in Washington on one side and a burgeoning number of folks who are natural old school, fiscally conservative, socially moderate Republicans who hate liberals but are too embarrassed by the no-nothings who have taken over the GOP to think of themselves as Republicans, and so are politically homeless.

These “real” Republicans, now called “independents,” are left to swing from left to right from election to election, as they did in 2004, 2006 and 2010. It also allows clever strategists like Karl Rove, in 2004 and, let’s hope, David Plouffe in 2012, to deploy a 50+1 strategy for re-electing presidents who, by all other metrics, should not be re-elected. All they have to do is get their entire base, which is, say, 45 percent of the electorate, to vote for their candidate, as well as 6 percent of the swingsters, resulting in a 51 percent victory.

So what is the solution for the “independents” and American Elects of this world? One way is for the Republican brand to finally become so tarnished by scandal that it has to be put down forever. It didn’t happen under Nixon or George Bush, so that is unlikely. But if it did happen, it would allow formation of a new party for fiscal conservatives/social moderates in which the Dixiecrat-teavangelicals would not be welcome.

OR — wait for it! — we could ditch our musty old 18th-century Constitution, with its antiquated, unworkable three-branch federal system and its bicameral legislature, and replace it with a modern parliamentary system, with a unicameral national legislature and judicial branch, but no presidency and no Senate.

I don’t see any other way for a “third party” to succeed.