Immediately after the news broke this morning that former Florida governor Jeb Bush had decided to get off the presidential sidelines and endorse former Massachusetts governor Mitt Romney , the political world wondered just one thing: Where does this fit in the Fix Endorsement Hierarchy?

In this Jan. 26, 2012 file photo, former Florida Gov. Jeb Bush speaks in Miami. Bush is endorsing Mitt Romney to become the Republican Party's presidential nominee. (AP Photo/Wilfredo Lee, File)

For those of you who are unfamiliar with our endorsement hierarchy, it’s our attempt to categorize and rank the various sorts of endorsements in the political world — from the genuinely meaningful to the utterly meaningless. A full list of the categories is at the bottom of this post.

In our endorsement hierarchy, Jeb for Mitt qualifies as a symbolic endorsement — one of the very few endorsements that can actually matter.

A symbolic endorsement is, put simply, support that goes beyond simply saying “I am behind this guy”. It sends a broader signal to either a party or the country.

When Massachusetts Sen. Ted Kennedy endorsed then Illinois Sen. Barack Obama in 2008, the message was clear: the last remaining scion of the most famous family in Democratic politics was passing the torch to the next leader of the party. It mattered more than just another senator throwing his support to Obama. A lot more.

Jeb Bush’s endorsement of Romney is meant to send an equally symbolic message to the Republican party. That message? Enough is enough.

(View the GOP endorsements tracker.)

Bush all but says those words in his statement endorsing Romney — congratulating all the candidates “for a hard fought, thoughtful debate and primary season” before adding: “Primary elections have been held in thirty-four states, and now is the time for Republicans to unite behind Governor Romney and take our message of fiscal conservatism and job creation to all voters this fall.”

The vision that popped to mind for us in reading those words was of Bush as the referee in a prizefight. After watching former Pennsylvania senator Rick Santorum absorb a series of haymakers from Romney, Bush is doing his best to step in and declare a technical knockout before things get any bloodier.

It’s no simple task given the divisions — both ideological and geographic — that have been made apparent in the primary fight between Romney and Santorum.

But, if anyone can make it all stop, it’s Bush. Here’s why: 1. He’s a member of the most powerful family in the Republican party. 2. He spent eight years as the governor of Florida, a critical swing state with a large Hispanic population. 3. He’s seen as the closest thing the party has to an honest broker, a guy driven far more by policy concerns than political ones and a guy who always has his eye on what’s good for the party.

It’s hard to see Santorum getting out of the race because Jeb Bush says he should. But the Bush endorsement of Romney will have significant reverberations across the media, activist and, perhaps most importantly, donor worlds that will likely have a negative impact on Santorum’s ability to move forward in a viable manner.

The one complicating factor in puzzling out the importance of the Jeb endorsement is the back story of why he decided to do it. Bush and those closest to him are mum on it but one senior party operative told the Fix earlier today that “he’s lost any hope that we’ll have anyone better.”

That sort of sentiment — if it becomes part of the storyline of the Bush endorsement — could lessen the endorsement’s impact somewhat. Still, this is a major moment for Romney and, his team hopes, symbolizes the beginning of the end (or maybe the middle of the end?) of the primary race.

The Fix Endorsement Hierarchy (ranked in order of influence)

* The Symbolic Endorsement: Former Florida governor Jeb Bush endorsing Mitt Romney for president.

* The National Endorsement: Former Minnesota governor Tim Pawlenty for Romney.

* The In-State Statewide Endorsement: Florida Gov. Charlie Crist throwing his support to Sen. John McCain just before the Sunshine State presidential primary in 2008.

* The Celebrity Endorsement: Chuck Norris for Mike Huckabee in 2008; Oprah for Obama.

* The Newspaper Endorsement: The Washington Post endorsing state Sen. Creigh Deeds in the 2009 Virginia Democratic gubernatorial primary.

* Out-of-State Statewide Endorsement: South Carolina Sen. Jim DeMint endorsing former Florida state House Speaker Marco Rubio in the 2010 Senate primary.

* The What Goes Around Comes Around Endorsement: Former New York City Mayor Rudy Giuliani endorsing Rubio.

* The Obligatory Endorsement: George W. Bush endorsing McCain’s presidential bid in 2008.

* The “Me for Me” Endorsement: Former senator Chuck Hagel (R-Neb.) endorsing Pennsylvania Rep. Joe Sestak’s (D) 2010 Senate campaign.

* The Non-Endorsement Endorsement: Louisiana Gov. Bobby Jindal (R) passing on an endorsement of Sen. David Vitter’s (R) 2010 reelection bid.

* The Backfire Endorsement: Former Vice President Al Gore endorsing former Vermont governor Howard Dean in the 2004 presidential race.

* The Pariah Endorsement: Jailed former congressman Randy “Duke” Cunningham backing Newt Gingrich.

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