Story highlights The Alabama Senate primary advances to a runoff next month

Ousted former state Supreme Court Chief Justice Roy Moore got 39% of the vote

Trump sent tweets and recorded a robo-call for Sen. Luther Strange

Birmingham, Alabama (CNN) The Republican runoff for a Senate seat here could become a six-week stress test for the already strained alliance between President Donald Trump and Senate Majority Leader Mitch McConnell.

The two have both pumped political capital into helping Sen. Luther Strange survive a stiff challenge from his own party.

They'll have to wade even deeper in the race if Strange is to win a one-on-one contest against the controversial, twice-ousted former state Supreme Court chief justice Roy Moore, who got 39% of the vote to Strange's 33% in Tuesday's primary, pushing the two into a September 26 runoff.

On Wednesday morning, Moore was already trying to drive a wedge between Trump and McConnell as he portrayed Strange as McConnell's lackey.

On morning radio shows, including WAPI 99.5 in Birmingham, Moore pointed to Trump's call for the Senate to abolish the filibuster and drop to a simple 51-vote majority to pass legislation.

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