The IRS targeting scandal is best understood as part of a larger effort to limit the political speech of conservatives and business groups. That became clearer last week regarding the Federal Election Commission, and now evidence is spreading to the Securities and Exchange Commission. Senior Republicans on the House Oversight Committee recently wrote to new SEC Chairman Mary Jo White to report on disturbing events that occurred under her predecessor, and to request agency documents. As at the IRS, there's an emerging pattern at the SEC of senior officials rolling over career staff to politicize the work of a powerful...