“Billionaire Ken Griffin has already invested roughly $40 million into this year’s midterm campaigns—a total that could easily double by November—as he works to try to shape the future of the Republican Party and help it hold its House and Senate majorities,” the Wall Street Journal reports.“Details of his giving, shared by two people familiar with it, reveal a megadonor focused heavily on Senate races. His single biggest gift so far this year was $10 million to the Senate Leadership Fund, a group aligned with Senate Majority Leader John Thune.”