This touring style of campaigning didn’t take place until the U.S. had developed a comprehensive railroad system in the latter 19th century. Before then, candidates courted the mostly white male, property-owning electorate through newspapers. In the earliest presidential elections, it was considered unseemly for politicians to tout themselves in public. No longer.

(Photo by Justin Sullivan/Getty Images)

In the age of super PACs and mega donors, candidates routinely charter flights across the country to get to and from big fundraisers -- but the bus is the standard bearer. Romney campaign buses have worn slogans such as "Conservative, Businessman, Leader" and "Every Town Counts." The Romney campaign bus, above, with its candidate in Tarlton, OH, at times does not even have the former governor on it, and will instead transport local politicians to rallies, or go on missions to taunt Obama supporters.

(Photo by White House Photographer Pete Souza)

President Obama, pictured here leaving Ireland in 2011, has to use Air Force One to travel by air, whether it’s official state business or part of his campaign trail. The president is supposed to reimburse taxpayers when the plane is being used for travel to fundraising events or stump speeches. One watchdog organization estimates that it costs over $180,000 an hour to operate Air Force One.

(Puck magazine, collected by Library of Congress http://www.loc.gov/pictures/item/91482121/)

The grassroots-style campaign for president became tradition by the time of Reconstruction, but, arguably, the first candidate to turn it into a national phenomenon was the populist Democratic nominee of 1896, William Jennings Bryan. Bryan conducted a six-week "whistle-stop" tour leading up to the election, usually giving 20 to 30 speeches a day.

Photo via Truman Presidential Library. (link: http://bit.ly/RkfR55)

Before Air Force One, there was U.S. Car No. 1. The Ferdinand Magellan was specially armored to carry President Franklin Delano Roosevelt during World War II. Harry Truman used the Magellan for his famous whistle-stop campaign during the 1948 election. One of the most famous moments of campaign history: Truman stood on the Magellan's observation platform, newspaper triumphantly hoisted high, holding the famously incorrect headline, “Dewey defeats Truman.”

(Photo by News bureau of United Air Lines-United Air Lines)

President Eisenhower was considered all but a lock for re-election in 1956, but at the Republican convention that year, a delegate wrote in “Joe Smith" for Vice President to protest the unanimity of the GOP nominations. Here, Democratic opponent Adlai Stevenson meets a Chicago supporter named Joe Smith before embarking on a tour of speeches with his campaign plane, the Joe Smith Express.

(Photo by Paul J. Richards/AFP/Getty Images)

With more campaign cash to go around, focus on the presidential primaries has grown over time. Coach buses allow candidates to travel to many destinations in one state, and have room for the media to come along for the ride. John McCain’s “Straight Talk Express” had a welcoming reputation among the press corps during his 2000 primary run.

Photo via Reagan Presidential Library

The Eisenhower administration retired the The Ferdinand Magellan due to lack of use in 1958. But it made a comeback in 1984 when President Reagan used it for one-day trip in Ohio. Campaigns have since brought back the nostalgic whistle-stop style, including President Obama in 2008 when the Illinois Senator campaigned on a restored Pullman car. McCain, who opposed Amtrak funding, carried on whistle-stopless.

FDR loved traveling by rail. He even had his own entryway to Grand Central Terminal in NYC, where a car specially designed for him* still sits, entombed and dusty, below the active station as we reported in our story on the lost subways of NYC. See pic here.

*An earlier version of this sentence incorrectly referred to this car as the Ferdinand Magellan.

Mitt Romney with South Carolina Governor Nikki Haley (photo: Romney campaign)

Four years ago, before the bi-partisan consensus on infrastructure spending had frayed, it might not have been remarkable to hear a Republican candidate for President say he -- or she -- believed in infrastructure spending, even if that meant borrowing. But in a year where Republican governors from Florida to New Jersey pulled the plug on big, already-in-the works projects, maybe it is.

"We're going to have to make an investment in our infrastructure and that's a place where if we make that investment, it will pay a return," Romney told a town hall meeting in Charleston, South Carolina December 17, expanding on remarks he made in New Hampshire last week.

And by infrastructure Romney took a broad view -- including roads, bridges, rail, ports, and air travel.

He also gave a little window into his economic theory.

"For instance, with regards to ports, as ports are dredged and made deep water ports and made more competitive they are then able to have more produce come in to them, more products come in to them and can charge therefore on the product coming in and can pay back the cost of the dredging or improvement," he said.

Here's a video posted by Building America's Future, a group that supports more spending on infrastructure. Full transcript of the exchange below.

Here's the transcript:

Question: What is your vision for improving our infrastructure system?

Romney: We got infrastructure issues in our ports, on our rail yards, on our aircraft systems, in our highways in particular.

I came in as governor of my state and my transportation people said that we had 550 structurally deficient bridges in my state. Five hundred and fifty. And we were spending $100 million a year on bridge repairs -- I doubled that to $200 million a year.

Now, that means I had to cut some other things to make sure we were able to put priority behind getting our bridges up to speed. We're going to have to make an investment in our infrastructure and that's a place where if we make that investment, it will pay a return. I don't mind borrowing if something has a revenue stream that will pay back the borrowing.

What I don't like is what we see in Washington where we borrow for just everyday expenses with no new revenue stream to pay it back.

But for instance with regards to ports, as ports are dredged and made deep water ports and made more competitive they are then able to have more produce come in to them, more products come in to them and can charge therefore on the product coming in and can pay back the cost of the dredging or improvement.

That's what's going to have to happen on our ports, on our highways, in our aircraft system.

We're going to have to make the investment to upgrade our infrastructure to make it competitive globally but also so our enterprises can be successful in moving products around. Then we can be competitive sending products around the world.

I recognize that America has to compete and for us to compete to have good jobs we have need to have good infrastructure and I'll stand behind --

By the way, the decision as to which ports to dredge and which rail lines to improve and which highways to get upgraded that's a decision to be made on analysis of need, a potential for return and opportunity not based upon politics.