Conventional wisdom has the Senate Republicans on the offense in 2018, but this new Tennessee poll calls that into question.

House Speaker Paul Ryan of Wis. administers the House oath of office to Rep. Marsha Blackburn, R-Tenn., during a mock swearing in ceremony on Capitol Hill in Washington, Tuesday, Jan. 3, 2017. (AP Photo/Zach Gibson)

Middle Tennessee State University polled the state checking up on the US Senate matchup between the likely Democrat, former Governor Phil Bredesen, and the likely Republican, US Representative Marsha Blackburn. This is the race to replace the retiring Bob Corker.

So it’s an open seat race, but Tennessee is very favorable ground for Republicans. Tennessee hasn’t elected a Democrat to the Senate since Al Gore in 1990. Fred Thompson and Lamar Alexander have since won the Gore seat. Bill Frist and then Bob Corker won the Class 1 seat currently up.

Yet Bredesen is up 10 points, 45-35, over Blackburn in this new poll! That’s a disastrous poll for Republicans, who expected this to be a safe seat to defend, in a year when they wanted to go on offense against Democrats.

If Republicans can’t even hold on to the seats they have, this Senate election may not go as well as they hoped.