The deadline for candidates to file to run in the August primary closed last Friday, and one of the surprises is that a competitive primary on the Republican side of this open-seat contest to succeed retiring GOP U.S. Sen. Bob Corker failed to materialize.

When Corker announced his retirement last September, it appeared that Republicans would host the kind of establishment v. conservative primary that has become all too common in Senate races. It appeared that the contest would be between U.S. Rep. Steve Fincher, representing the more establishment wing of the party, and U.S. Rep. Marsha Blackburn, who is carrying the conservative banner. There was likely to be a third candidate, probably former state Rep. Joe Carr who ran in the 2014 primary against U.S. Sen. Lamar Alexander, taking 41 percent, would run as the anti-Washington conservative outsider. Carr decided to seek a vacant seat in the state Senate instead. Fincher announced in February that he would not run and encouraged Corker to rethink his decision to retire.

Once the dust cleared this week, Blackburn is the only first-tier

More from the Cook Political Report