As a finicky libertarian who is too much of a purist to back any of the major party candidates and too much of a pragmatist to vote third party, I have no dog in this 2016 presidential fight. But I do have the hope of a legitimately interesting general election — and specifically, the slight but tantalizing possibility of a four-man race.

The ideal line-up: Bernie Sanders (D) vs. Donald Trump (R) vs. Mike Bloomberg (I) vs. Gary Johnson (L).

This foursome would give us more interesting general election debates than we've seen in years, featuring, respectively, representatives of the socialist left, nationalist right, statist center, and cosmopolitan libertarianism.

On the debate stage, pairings and contrasts would emerge on an issue-by-issue basis: Raise taxes? Sanders and Bloomberg. Mass surveillance on ordinary Muslims? Bloomberg and Trump. Reduced American presence in the Middle East? Sanders and Johnson. Abolish the Department of Education? Johnson and Trump. Restrict immigration to help American workers? Trump and Sanders (yes, really).

Here's how we get there in four steps.

First, Trump and Sanders must snag their nominations — hardly an impossibility at this point. Trump retains a substantial national lead, and seven in ten Republicans believe he'll win the nomination.

Sanders recently surpassed Hillary Clinton in national support for the first time, and some polls suggest he's Democrats' stronger option against Trump. Whether he'll be able to maintain momentum in the South remains to be seen — Clinton currently outpaces him two-to-one in South Carolina — but his campaign is far from the longshot it once seemed.

Second, Bloomberg must get in the race as an independent candidate. This step is comparatively easy, as he has already indicated an interest in running. Bloomberg seems most likely to jump in if Sanders is nominated, and indeed polling indicates he performs better against Sanders than Clinton, as he can more easily pick off centrist Democrats. Bloomberg's high-profile gun control advocacy could also drive Democrats his way if Sanders, who has a notably mixed record on guns, is the alternative.

Now, to be fair, this is not the first time Bloomberg has toyed with the idea of a presidential run. But it's not Trump's first time either, so maybe this is the year of New York billionaires finally going through with their campaign fantasies.

For the third step, we return to Republican voters, now stuck between two rocks and a very hard place. From their own party, on offer is a candidate who "just about runs the table on the seven deadly sins;" is fiercely opposed by respected religious and political conservatives; and has embraced positions anathema to the average Republican, like funding Planned Parenthood and the ObamaCare individual mandate. That a third of Republicans support Trump means two out of three prefer someone else — in fact, despite his impressive showing on Tuesday night, he is second only to Jeb Bush in unfavorability among GOP voters.

But what's the alternative? A self-identified socialist in Sanders and a gun control advocate and all-around nanny statist in Bloomberg. That's where Johnson comes in.

For some Republicans desperate for a palatable vote in 2016, former (Republican) New Mexico Gov. Gary Johnson could fit the bill. He's never been my preferred libertarian candidate, but the very reasons I critique him (primarily, a semi-interventionist foreign policy including belligerence toward Iran, willingness to launch humanitarian missions and drone strikes, and paranoia about Muslims) probably make him more appealing to some in the GOP.

True, Johnson, now CEO of a Nevada-based company that actually sells cannabis, is more enthusiastic about marijuana than conservatives might like under normal circumstances, but remember the alternatives. (Actually, by November, Republicans may be feeling the need to become Johnson customers as well as voters.) And anyway, when it comes to weed, the times are changing. Two in three Republicans favor marijuana reform, so that — plus Johnson's other socially liberal views — could well be an acceptable price to pay for his strict fiscal conservatism backed by a strong record as governor, where he left his state government substantially smaller and running a $1 billion surplus.

Fourth and finally, though the general election debate stage has held only Democrats and Republicans since Ross Perot's run in 1992, this time around, additional participants are not inconceivable. The minimum requirement is 15 percent support in national polls, and with major party picks as polarizing as Trump and Sanders, Bloomberg and Johnson could meet that mark.

In fact, the leaders of the Commission on Presidential Debates (CPD) said in January that they could see exactly such a dynamic. "The dynamic in the electorate right now and the dissatisfaction with the two major political parties could very conceivably allow an independent or a third-party candidate to emerge," commented CPD co-chair Michael McCurry, "and we are very clear that they would be welcome in these debates."

Any other year, 15 percent would be an almost unattainable benchmark for an independent or Libertarian Party candidate to hit before having the exposure of the debates. This time, though, it could happen — and it should. A Sanders-Trump-Bloomberg-Johnson race is the election America deserves, a thorough upending of establishment politics and a true exercise in political diversity.

Yeah, Trump would probably win. But that might happen anyway. Let's at least have a good conversation on the way.