GOP senator's aide joins Trump campaign
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A top aide to Sen. Jeff SessionsJefferson (Jeff) Beauregard SessionsGOP leaders to Trump: Leave Mueller alone FBI chief refuses to deny reports he threatened to resign amid pressure House Judiciary Chair expected to issue DOJ subpoena over Clinton emails as soon as this week MORE (R-Ala.) is joining Republican presidential front-runner Donald TrumpDonald John TrumpKoch-backed group launches six-figure ad buy against Heitkamp Anti-abortion Dem wins primary fight Lipinski holds slim lead in tough Illinois primary fight MORE's campaign, according to a new report.

Stephen Miller, who served as Session's communications director, will join Trump's campaign Wednesday as a senior policy adviser, The Washington Post reports.

Trump continues to dominate in the GOP presidential race a week out from the first ballots being cast in the Iowa caucuses.

The businessman has boasted of relationship with Sessions, who hasn't yet endorsed a candidate but appeared at a Trump rally in Mobile, Ala., in August.

Sessions, whom Trump consulted on his immigration proposal, briefly wore one of the candidate's "Make America Great Again" hats at the rally before making remarks.

Miller will work alongside Trump's chief policy adviser Sam Clovis to draft white papers and aid the candidate as he prepares for the Thursday night GOP debate, according to the Post.