President Dwight D. Eisenhower is riding down SW Broadway in this undated LIFE magazine photo. I believe this is 1956, as he made a west coast swing in October of that year during the presidential campaign. He’s riding in the “bubbletop” 1950 Lincoln Cosmopolitan limousine which I don’t think would have been available to Ike in 1952.
The cross street immediately behind him is Washington Street. The Plaza Hotel is now Hotel Vintage Plaza and the Bank of California building replaced the Union Pacific and Liberty Theater block on the left.
(LIFE)
Vintage Portland 
The Benson Hotel had a big neon sign? Wow. I’d love to see closer photos of that!
Was looking for a picture of the Liberty Theater (you can barely see its sign on the left) when I found this entry. Here’s what it looks like today: http://is.gd/IYTzaq
Eisenhower’s motorcade passed by St. Mary’s Academy and all of us students were allowed to go out and watch but I could not remember exactly which year. So glad to find this photo as I graduated in 1958.