I didn’t really notice the “tallyban” business. I stopped paying attention to Obama’s pronunciations when he made the famous “race” speech and said “divissive” instead of “diveyesive”.
(Yes, I’ve heard the arguments that “divissive” is a regional pronunciation, or an acceptable alternative, or whatever; and I know he’s not the first to say it that way, but then GWB wasn’t the first to say “nucular”.)
It’s like the time I heard the BBC’s Washington correspondent pronounce “Maryland” exactly as spelled (for non-Americans, Maryland should rhyme with Marilyn, as in Monroe). Throw in the times I’ve heard their correspondents call Houston “Whoston”, and I’m unable to completely trust the way any of them say any place name.
Funny thing is most Tex-Mex Hispanics I’ve known will pronounce words just the way they’re commonly used, except of course when they’re speaking Spanish – which (guess what!) is a different language.
Most notably, if you’re from Austin, you’ll know that everyone, Hispanic & non-Hispanic alike, will refer to local avenues as “Man-Shack” (Mancha) Boulevard and “San Juh-Sin-Tow” (San Jacinto) Blvd.
As for Obama, if wants to use a soft “t” in pronouncing “Taliban” when he’s speaking Urdu, more power to him. But when speaking English, frequent & deliberate use of foreign language pronunciation comes across as a bit of a silly affectation.