Easily. The terms predict and claim are pretty much synonymous. In fact, wikipedia defines prediction as such:
"A prediction is a statement or claim that a particular event will occur in the future in more certain terms than a forecast."
From ask.com:
"Predictions are probabilistic estimates of future occurrences based upon many different estimation methods, including past patterns of occurrence and statistical projections of current data."
Jes' sayin' it's not unreasonable to ask someone to back up what they say, be it a claim or a prediction. I don't think any of the three of them would go much out of their way to see Bush tried (what a mess when there are much more important issues to get to first), but if forced to confront such a problem, Obama has outspokenly challenged the president more consistently than the other two and when he's done it when it wasn't politically palatable.
Unlike Hillary Clinton, who's opinions and statements have often seemed to reflect the polls. I could see Hillary prosecuting him if a majority of Americans were clamoring for it but talk about polarizing the country and the White House from the get-go otherwise... it would hurt her worse than anyone else.
yr ronin,
joey