The Republican National Committee is on track to spend more than $100 million in the midterm campaign, with virtually every dime plowed into the party’s new digital voter-turnout program. If the program is effective, Republican campaigns will have access to a modern get-out-the-vote operation that has been the hallmark of the Democrats’ success in recent election cycles. But if it fails to deliver as advertised, Republican candidates will be stuck with another subpar voter turnout program and without the resources the GOP traditionally sent to their campaigns in midterm years. The RNC is set this week to announce the deployment...