Colombia ? Sen. John McCain arrived here Tuesday night on his third foreign trip since clinching the Republican presidential nomination, the latest attempt to embellish his international credentials at a time when the electorate is increasingly focused on domestic issues.

McCain’s latest trip – to Colombia and Mexico – is designed to highlight his positions on trade and, to a lesser degree, immigration. Its value has been questioned by campaign strategists in both parties, since neither issue seems a winner for his campaign. His insistence on the virtues of free trade remain suspect in Rust Belt swing states, and his position on immigration continues to make many conservatives wary.

That raises a difficult question for his campaign: Can a presidential candidate really win by “expanding the map” to Mexico, Colombia, Canada and Europe?

Speaking to reporters on his arrival in Colombia, McCain, R-Ariz., said he will stick by his support for free trade because “I have to do what I think is right for America. But I want to add very quickly: I understand the pain people are going through. I understand the challenges.”