Last February, as Mitt Romney inched closer to the Republican nomination, two of his opponents hatched a plan to stop his momentum. Rick Santorum and Newt Gingrich decided they might fuse their campaigns, presenting a united alternative to Romney. The plan never came to be — but it doesn't matter. It wouldn't have worked.

Bloomberg Businessweek's Joshua Green pulls back the curtain on the behind-the-scenes maneuvers:

The discussions between the two camps commenced in early February, just after Gingrich got trounced in Florida. [Santorum strategist John] Brabender called members of the Gingrich brain trust, hoping they could persuade Gingrich to drop out and endorse Santorum, who was rising in the polls. “I’ll tell you this,” says Brabender, “If Gingrich had dropped out at the right time, Santorum would have been the nominee.” Brabender wasn’t short on moxie: He wanted Gingrich to declare in the middle of a nationally televised debate that he was dropping out and endorsing Santorum. “I couldn’t write an ad to match the political theater that would have created,” he says.

The plan fell apart for precisely the reason you'd expect: both Santorum and Gingrich wanted to be the top name on the ticket.

That argument was futile, because a Santorum/Gingrich bill would have had no more luck beating Obama than would a Gingrich/Santorum ticket. And even that was a futile conversation, because a unity ticket wouldn't even have come close to beating Romney in the primaries.

Why a Unity Ticket Wouldn't Have Beaten Romney

Of course, it's impossible to be sure what would have happened given such the dramatic move Santorum's aide offers above. Perhaps this would have sparked some as-yet-unseen passion for Santorum outside the conservative base of the party. Who knows. But looking at the numbers, it seems clear that the idea was a nonstarter.

During the course of the primary, Romney won 37 states to Santorum's 11 and Gingrich's two. The total delegate count put Romney well over the required 1,144; neither Santorum or Gingrich topped 250.

Here's what the map looked like at the end of the primary campaign. States Romney won are in red; Gingrich, yellow; Santorum, blue.

If you went back and adjusted the results for each state to compare Romney's total against Santorum and Gingrich's combined, the map changes to this:

You'll notice there's not a lot of change. The only states that jump from the Romney column to the Unity column are Alaska, Michigan, Ohio, Wisconsin, and Wyoming.

Your first thought may be: Hey! Ohio and Michigan have lots of delegates. Which is a fair thing to think.

So here's the national map showing Romney's delegate lead pre-unity ticket. (In short, it's a comparison of Romney's delegates to Santorum and Gingrich's combined.) The bigger the circle, the higher the delegate total.

And here's that map if we assume that all Romney delegates in each state that moved to the Unity ticket were allocated to that ticket.

Without the Unity ticket, Romney picks up 1,575 delegates, including unattached party delegates. With the Unity ticket? His total drops 125 delegates. Even if you assumed the unattached delegates go to Unity (which they wouldn't, for reasons explained below), Romney still gets 1,296 delegates — 150 more than he needs to secure the nomination.

Oh, by the way: The Unity ticket would only have come into being after the Michigan and Wyoming primaries.

Why a Unity Ticket Wouldn't Have Beaten Obama

Well, for one thing, it wouldn't have gotten the nomination. But even if it had (in the "Romney is hit by a bus" scenario), the Unity ticket was meant to solidify conservative Republican voters against a candidate perceived by many in the party to be too moderate. In a general election, that more conservative ticket would have fared worse than Romney did. For as poorly as Romney did with independents, a Gingrich/Santorum/vice-versa ticket would have done far worse. Which is why party delegates would have thrown their weight behind Romney.

Again: Nobody knows how an unprecedented announcement of unification would have altered states later in the campaign. Perhaps it would have been enough to drop Romney under the 1,100-delegate level and into a floor fight — a fight Romney would likely have won.

Rick Santorum and Newt Gingrich lost the Republican primary in part because people rejected their ideas. They would have rejected this one, too.