One of the overlooked downsides to the electoral wipeout the Republican Party has endured in the past two election cycles is how those elections have drastically shrunk the amount of Republicans who are nationally prominent. Without the Presidency, and the loss of Governors, Senators, and Representatives, there aren't very many potential leaders left among Republicans. Also, even the most loyal party man surely isn't enamored with every Republican elected official. What you hear these days is a cry wondering where Republican leadership is. Debates about who is the "leader" of the Republican Party are distracting at this point, but there seems to be a paucity of those who could even be in the discussion. Republicans have a short bench problem, which hurts their ability to have national leadership in Congress, in the states, and in the future, in the White House.
Governors
In the 1990s, Republican Governors (along with some big city mayors) were instrumental in making public policy changes that would eventually be successful at the national level. Part of the reason why Bush's 2000 campaign was successful was because he made himself the custodian of the achievements that Tommy Thompson, John Engler, Rudy Giuliani, and even Bush as Governor achieved.
There are 22 Republican Governors at the moment. What is more distressing is how few innovative leaders there are among Republican Governors. Many Republican Governors are governors of small Plains or Rocky Mountain States that are invisible on a national stage. There is surprising vitality in New England with three GOP governors, but they are generally too moderate for the national Republican Party. Two standouts who deserve some national attention are John Hoeven from North Dakota and Donald Carcieri of Rhode Island. Hoeven was reelected last year with 74 percent of the vote when McCain only received 53 percent. National Republicans have begged him to challenge the state's two Democratic Senators. Carcieri somehow managed to be elected twice as an actual conservative in one of the most liberal states in the country. Neither is of Presidential timber, but they could be excellent future Senatorial candidates or national Republican voices.
Some Governors have been failures (Schwarzenegger), some are good for their state but too moderate nationally (other New England governors, perhaps Crist), some have just been installed in the past year, and at least one is too busy in Argentina to be taken seriously. I would say there is a handful of top tier Republican Governors at this point. Bobby Jindal, by his own acknowledgment, is too green to make any moves yet. John Huntsman is certainly a formidable figure, but he also is a more long-term hope considering he will be Ambassador to China for the next few years. Haley Barbour has generally been a successful Governor of Mississippi and could fill the Southern slot in a primary. Tim Pawlenty has been a rare blue state Republican in recent years. I think he is likely to be a 2012 candidate and would be considered a top contender if he ran. The crown jewel, in my opinion, is Mitch Daniels, Governor of Indiana. He's probably the best Republican politican in America right now. Earning nearly 60 percent of the vote last year when Obama won Indiana indicates he has some crossover appeal. He claims that he is not interested in seeking higher office, which is a real shame.
Senators
Republicans have lost 15 Senate seats in the past three years. This attrition clears out opportunites for Republicans to come up with national leaders. The 40 Republicans left are bereft of national figures. McConnell is a master floor manager but no national spokesman. McCain is a real leader, but his national campaign days are over. The GOP caucus is dominated by Southern good ol' boys and small state senators. Guys from Wyoming or Idaho won't find national traction and the good ol' boys are better vote jockeys than communicators.
I would say the following Senators are, or could be, good national leaders for Republicans: John Kyl, Judd Gregg, Tom Coburn, Jim DeMint, John Thune, and Bob Corker. Coburn and DeMint already are good conservative voices in the Senate, but would never be Presidential material. Kyl does a good job on Judiciary, but is somewhat in the shadow of McCain. To my mind Gregg has been the most articulate Senator in the past year, but he always indicates that he wants to retire. Corker is still a freshman, but was the point man for GOP efforts on the car bailouts. Thune is also a freshman, but is the youngest Republican Senator by a mile. There are virtually no 2012 Presidential candidates in the Senate. I believe this is why Ensign was trying to run for President before his affair was disclosed. Of the entire Republican Senatorial membership, I could only see Thune having a serious campaign in 2012.
Others
Members of the House of Representatives are not national leaders (Speaker of the House exempted). Impressive Representatives like Paul Ryan and Mike Pence would need to become Senators or Governors to have a real shot at the Presidency. If Jack Kemp couldn't win the nomination from the House, then I don't think any non-Speaker would be able to.
Of course, there are still the retired political figures and those who were candidates last time. Romney seems a near lock to run again and would have to be considered the frontrunner. Huckabee will never be President, but he may run, especially if no Southerner is in the race. I think Palin's resignation indicates she won't run in 2012, but she still is young and already has a big national following. I don't think we'll see another Wesley Clark/Fred Thompson fantasy candidate next time.
Conclusion
The Republican bench is very thin at this point. If you are looking towards 2012, I would predict right now the only serious candidates who will run are Romney, Pawlenty, and Barbour. Daniels would certainly be in that grouping if he decided to run. Sure, you would get the Tom Tancredos of the world running no shot campaigns, but those candidacies are irrelevant. I think beyond 2012 Jindal, Huntsman, Thune, and perhaps Palin 2.0 would be serious Presidential candidates. There really is a leadership vacuum in the Republican Party right now. A smart, ambitious Republican could certainly find an easy path to the top.