Remember that his beliefs are now conflicted. That is, he probably has no problem with this bird being fried, but as President, he has to worry about a quid pro quo, other governments, not just the Mexicans, doing the same to US citizens over there.
It’s pretty common practice overseas in less than honorable countries, to round up Americans on trumped-up charges for political reasons. And that gives the US only two options—invoking international law or going to war. And our case for international law is a lot better if we are in compliance with it.
And the international situation isn’t getting better, it’s getting worse. What with that kangaroo court of the ICC, European wide arrest warrants, and local judges who decide to arrest Americans they think are CIA agents because they don’t like them, etc.
But the bottom line is that Bush, or any President, cannot stop Texas from executing murderers; but he has to at least ask.
Sounds like you have the best answer.