With the presidential election just four months away, speculation is swirling about who Mitt Romney will select as his vice-presidential running mate. There are a number of factors that presidential candidates consider when deciding on who will fill the number two spot on the ticket. Some presidential candidates prefer a running mate who will shore up support among a particular voting bloc such as women or Hispanics, while other candidates might select someone who can help deliver a key swing state come November. While Governor Romney will no doubt consider someone who can help his candidacy in one or more of those ways, he has repeatedly said that his first priority in choosing a running mate is to find someone who will be ready to step into the presidency on day one. In my view, there are six individuals who stand out as the most logical choices for Mitt Romney. First and foremost would be up and coming Florida Senator Marco Rubio. While some argue that Rubio is not quite ready for the vice-presidency, I think the pick makes sense for two reasons. First, the selection of Rubio could help to ensure that Mitt Romney wins the state of Florida and it's twenty-nine electoral votes. Second, as the son of Cuban immigrants, Rubio could help Romney close the gap among Latino voters who will no doubt play a key role in electing the next president. New Jersey Governor Chris Christie would bring not only valuable executive experience to the ticket, but some would also argue that the selection of Christie would bring some much needed enthusiasm and excitement to the campaign as well. Some have suggested that if Christie is the pick, he might overshadow the man at the top of the ticket due to his popularity among many Republicans. Representative Paul Ryan of Wisconsin appears to be another front runner for the number two job. Ryan currently serves as the chairman of the House Budget Committee. With the economy being the number one issue for voters this election year, many would say that the selection of Paul Ryan would be the best pick that Romney could make. Wisconsin's status as a swing state in this year's election could also persuade Governor Romney to give the nod to Representative Ryan. Former Minnesota Governor Tim Pawlenty, who is currently on the campaign trail in Ohio as a surrogate for Mitt Romney, would be one of the safest picks that Romney could make. Pawlenty would be considered by many to be one of the most conservative selections that Romney could make. In a state that usually votes Democratic in presidential elections, the selection of Pawlenty could help turn a traditionally blue state red this November. Romney would surely like the fact that as a former governor, Tim Pawlenty, like Chris Christie would bring valuable executive experience to Romney's campaign. Senator Rob Portman of Ohio is also receiving a lot of attention as a possible running mate for Mitt Romney. Portman would be a beneficial addition to the Republican ticket for two reasons primarily. As the former director of the Office of Management and Budget, many would argue that Portman would bring valuable economic experience to the vice-presidential slot. Senator Portman also served as U.S. Trade Representative from May 2005 to May 2006 further solidifying his economic credentials. Needless to say, Ohio is key to a Romney victory in 2012. As a matter of fact, no Republican has ever won the presidency without winning Ohio. Knowing that Senator Portman could help deliver Ohio for Mitt Romney, one would be foolish to think that Governor Romney isn't giving him serious consideration. Perhaps the most surprising pick that Mitt Romney could make would be that of Senator Kelly Ayotte of New Hampshire. While New Hampshire will be a key swing state in this year's election as well, I have a hard time believing that Mitt Romney would select Senator Ayotte for the sole purpose of winning the state since it only has four electoral votes. I could see Romney selecting Senator Ayotte to help secure more votes among women nationwide, but at the same time, as a relatively unknown in the world of politics, I see Kelly Ayotte as a very risky pick. Given the fact that Senator John McCain went with a relatively unknown in 2008 by selecting former Alaska Governor Sarah Palin as his running mate, I can't see Romney doing the same in 2012 especially given the outcome of the 2008 presidential race. Trying to predict who a presidential candidate will select as their running mate is like trying to predict which numbers will win you the lottery. It is usually a very difficult thing to do. Who will be the winner of the 2012 Romney veepstakes? Your guess is as good as mine.