A new public opinion poll suggests some significant shifts in how Oregonians are thinking about the slate of presidential candidates. 

Mike Riley, of Riley Research, questioned likely voters throughout the state. He says the most dramatic shift concerned Rudy Giuliani’s support among Oregon Republicans. The candidate went from 33% down to 16% in the last 3 months. 

Riley, who spoke with Allison Frost, says other Republicans made up the ground he lost.

The poll's margin of error is 4.86%.