Jonathan Gruber, the MIT professor, who has done extensive modeling of U.S. health care systems. Gruber advised Massachusetts Governor Romney in crafting the health care law in that state. He also advised the Obama administration in crafting the health care mandate that requires all Americans to buy health insurance to keep costs down. Gruber estimates the number of newly insured Americans could drop to 8 million from an estimated 32 million if the Supreme Court strikes down the health care law mandate. The result he believes will drive insurance premium prices even higher.