Since sleeping in your own bedroom is not a tax-deductible business expense, those per diems (and perhaps the travel expense for Palin’s children traveling with her) represented taxable income to Palin. As far as I know, she hasn’t released her tax returns yet, but there could be an explosive issue there. Voters don’t like petty chiselers, and they don’t like tax cheats.
She released her tax returns as part of the vetting process, but has not done so publicly yet.
Did the McCain campaign invite a tax cheat onto the ticket?