It turns out the Bush-Truman comparison is a pretty good one in terms of both trends and levels of approval. Truman’s bounces are similar to those of Bush and the current level of approval and its trend are quite close. In comparison, Johnson did better throughout his war, while Nixon sank lower and quicker as Watergate came to dominate public perceptions.
Is Bush the New Truman? (Political Arithmetik, complete with pretty graph)
Just to nudge it along a little, because it’d be nice to see Bush win something for once: