The Republican National Convention kicks off in Tampa, Fla., in less than a month, and it’s time to answer the really big question: Who will presumptive nominee Mitt Romney choose to showcase in prime time with a coveted keynote speaking slot?

Using CQ Weekly’s 2008 Republican Convention Guide, I’ve identified at least 15 openings, including those reserved for the nominees for president and vice president. But we’ll round up to a “top 20” and try to determine who might help Romney draw a television audience, excite the Republican base, appeal to independents and soft Democrats and — most importantly — prime the pump for his candidacy and his message.

Category one consists of those who are definitely, or at least highly likely, to get airtime. Some might not speak in prime time but by virtue of their position will receive star treatment. They are: Romney; his wife Ann; the eventual vice presidential running mate; Speaker John Boehner (Ohio); Senate Minority Leader Mitch McConnell (Ky.) and Republican National Committee Chairman Reince Priebus.

Category two includes Romney’s top surrogates, including those who are loyal, politically important or both. Romney’s universe of active surrogates has broadened since early April, when it became apparent that he would win the nomination. This category includes only those who delivered their support at a crucial time in the primary and carried high political value. Many are on analysts’ short list for vice president (including mine).

On this list are Sen. Kelly Ayotte (N.H.); Senate Republican Conference Vice Chairman Roy Blunt (Mo.); House Majority Leader Eric Cantor (Va.); Rep. Jason Chaffetz (Utah); New Jersey Gov. Chris Christie; Puerto Rico Gov. Luis Fortuño; South Carolina Gov. Nikki Haley; Virginia Gov. Bob McDonnell; 2008 nominee Sen. John McCain (Ariz.); former Minnesota Gov. Tim Pawlenty; Sen. Rob Portman (Ohio); Sen. Marco Rubio (Fla.); House Budget Chairman Paul Ryan (Wis.); and Sen. John Thune (S.D.).

I’ve reserved category three for important figures in the Republican Party, both past and present. Some might not have formally endorsed Romney in the primary. Some, in fact, might have endorsed one of his opponents. But all have been helpful since Romney emerged as the presumptive nominee, and none would appear to be considered an enemy of the former Massachusetts governor’s campaign. Some of them also are on various dark horse running mate short lists (again, including mine).

They include former Mississippi Gov. Haley Barbour; former Florida Gov. Jeb Bush; Texas Senate nominee Ted Cruz; Indiana Gov. Mitch Daniels; Sen. Jim DeMint (S.C.); Louisiana Gov. Bobby Jindal; former Alaska Gov. Sarah Palin; Sen. Rand Paul (Ky.); Sen. Pat Toomey (Pa.); former Arkansas Gov. Mike Huckabee; Rep. Allen West (Fla.); Arizona Gov. Jan Brewer; New Mexico Gov. Susana Martinez; Nevada Gov. Brian Sandoval; and Wisconsin Gov. Scott Walker.

In category four, we have the losing 2012 GOP primary candidates: Rep. Michele Bachmann (Minn.); businessman Herman Cain; former Speaker Newt Gingrich (Ga.); Rep. Ron Paul (Texas); Texas Gov. Rick Perry; and former Sen. Rick Santorum.

Among the three-dozen possible keynote speakers I’ve outlined, not including Romney, his wife and his running mate, obviously not all of them will make the cut. Additionally, there are some that are not a good fit for the task at hand.

This category could include Blunt, who ran Romney’s endorsement whip operation on Capitol Hill but is more of a behind-the-scenes operator than a prime-time speaker, or Santorum, who is notorious for veering off script and has been slow to embrace Romney despite having formally endorsed him since dropping out of the primary in April. With that in mind, here are my locks to receive an invitation to deliver a prime-time address:

Ayotte, (Jeb) Bush, Cantor, Christie, Daniels, Haley, Jindal, McDonnell, Martinez, McCain, Pawlenty, Rubio, Ryan and Walker. Add the guaranteed slots for Romney, his vice president, his wife, Boehner, McConnell and Priebus and that’s your top 20, America.

Honorable mention: Either Ron or Rand Paul. If Ron Paul is willing to endorse Romney in his speech, he could receive a speaking slot. If not, Rand Paul, who has publicly backed Romney, gets the mic.