I think that Republicans need to take the high ground here. I know very little about Tom Daschle but he seems to be well respected, especially in Healthcare. The best course of action here is simply to express regret for the impact on a experienced public servant.
Regret that the tax code as implemented and manipulated over the years is continuing to cause President Obama issues. I believe that Republicans can begin to ask the simple questions about simplifying the tax code. Not by creating more exceptions for rich folks who get favors (like Daschle) but more to a simple tax code.
I am a recent convert from a flat tax to the Fair Tax due to an issue that is center to this argument. That issue is compliance. How difficult is it to track a foreign organizations payments to a US citizen, as in the case of Geitner? Or a gift of services as in the case of Daschle? A flat tax would likely have the same issues of compliance as the current code where that payments were simply not made. Or in the case of gifts the flat tax may simply avoid counting that as income and allow wealthy gifting to become the norm. The Fair Tax (National Consumption Tax) would tax the spending done after the income. Any services purchased even gifted have an added tax which would have been paid by the service company in either case. Income foreign of domestic is not a concern as the money spent locally is taxed. This Fair Tax also gets federal income from the wealthy as they spend their wealth.
Now is the time to take the mantel forward.