This quarter’s campaign finance report shows that the world’s richest man is the top political donor of this midterm election. Our reporter Theodore Schleifer explains how Elon Musk came back from a brief rift with President Trump and Republicans to become a central player in the party’s campaign to hold Congress.

Republican Senate and House candidates are being out-raised by their Democratic rivals, but the party has received a huge boost from groups tied to Elon Musk and President Trump.

The world’s richest person, who has become the biggest known midterm donor, gave $158 million to a group that quickly spent that much to help Mr. Paxton’s Senate bid in Texas.