Who can best help President Obama push through health care reform? The Post asked some Beltway observers for their thoughts, now that tax troubles have aborted the nomination of Thomas A. Daschle for secretary of health and human services and White House health czar. Below are contributions from Robert Shrum, Robert Moffit, Ruy Teixeira, Frank Micciche, William A. Galston, John Seigenthaler, Robert J. Blendon, John Goodman, Georges C. Benjamin and John Dingell.