[Boot Hill]

John H K asks:   "Make me a case as to why Iraq had a specific beef against Daschle and Leahy..."

Your question is flawed because it presumes something not in evidence, i.e., "Iraq had a specific beef". If you remove the presumption, then your question answers itself, they were targeted simply because they were prominent government officials.

--Boot Hill

[muawiyah]

Or, not merely prominant government officials, but those with a Capital Hill mailing address.

A terrorist who knew the routing single-piece FCM might take from entry at Boca Raton to DC could have been aiming to disable several important postal facilities.