Steps by Sen. Rand Paul (R., Ky.) toward launching a presidential campaign in the wake of his party’s midterm sweep are raising questions about the role of his political mentor and father, former Texas Rep. Ron Paul.

The elder Mr. Paul isn’t expected to be there on Wednesday when his son convenes political advisers from around the country for a private powwow in Washington, the latest sign that the 79-year-old former congressman may be on the sidelines of his son’s expected White House bid.

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