Who

Ron Paul, the libertarian-leaning Texan congressman whose small but vocal fan base is trying to grow beyond his niche appeal.

What

Paul's team is pushing out a $1m campaign, featuring its third advert called "A Veteran's Best Friend".

When

It will play in all the vital early states of New Hampshire, Iowa, Nevada and South Carolina.

How

It is hard to imagine a more basic and straightforward political advert. In a field infamous for not-very-subtle tricks and twists of the truth, this ad plays like the sort of straight shooter that Paul claims to be. It has almost no policy implications; it does not attack a rival. It starts off with a scene straight out of Apocalypse Now with old flyover footage of Vietnamese jungle. Veterans Joe Pena and Rene Reyes then talk about the Viet Cong, their experiences – and the comrades who never came back. The two veterans were never thanked for their service, they say, until Paul helped them get their medals.

Why

This fascinating ad accomplishes several things. First, Paul is a rare politician in that he openly criticises American foreign policy and has been vocally anti-war (from the principle that they cost too much and damage America's international reputation). So, this is a firm defence against those who portray Paul as unpatriotic and anti-military.

Second, it fills in crucial biographical information: Paul served as a flight surgeon from 1963 to 1968. Next time he is attacked for his anti-war stance, people might remember this ad and recall that Paul knows the military at first hand. As Pena says, "It takes a veteran to understand a veteran and he is a veteran himself."

Veterans are, moreover, an important and esteemed voting bloc in their own right. And Paul's campaign says he receives more donations from active military personnel than all the other GOP candidates combined.

According to polling, Paul is tucked in third place behind the two leading candidates, Rick Perry and Mitt Romney. For a candidate used to being an outsider and "no hoper", that is not a bad place to be. And this ad can be seen as an attempt to mainstream Paul's appeal: this is his shot at playing down his fringe rep and looking more like a cookie-cutter Republican candidate. It's patriotic, biographical and no American could disagree with a word of it. There is nothing here on scrapping the department of education and abolishing the Federal Reserve.

The fact that this ad will play in four states is also a big point. Paul clearly has the money and the will to stay the course.