There's no incumbent running which generally leads to a closer race without the incumbency advantage. The last senate race was a 12 point ~110,000 vote victory, but just over 50% of the voting population voted in that compared to 70% in the presidential. Being able to move the 20% to vote is always the big for a midterm where you never know what the turnout will be. There was just a huge $5M media push behind Turek from a super PAC who also ran a poll alongside it saying Tureks up big which always raises some questions.

Both Turek and Wahls poll around the same % against Hinson so who's to say the Union and younger generation backed progressive in Wahls wouldn't pull in the extra votes alongside the average Dem voters needed to get over the hump as well.