The Obama administration is quietly diverting roughly $500 million to the IRS to help implement the president’s healthcare law. The money is only part of the IRS’s total implementation spending, and it is being provided outside the normal appropriations process. The tax agency is responsible for several key provisions of the new law, including the unpopular individual mandate. Republican lawmakers have tried to cut off funding to implement the healthcare law, at least until after the Supreme Court decides whether to strike it down. That ruling is expected by June, and oral arguments last week indicated the justices might well...