The 72% approval startled some people in my Twitter feed in Minnesota and around the country. That number shouldn't surprise anyone considering Klobuchar received 65.23% of the vote to GOP nominee Kurt Bills' 30.53%. Picking up ~7%, for a Democrat, moving from actual vote share (with a named opponent) to just a share of the state's registered voters is absolutely a reasonable figure. I haven't seen any push-back from the Minnesota GOP, which is an indication that they are seeing the same thing. The Minnesota GOP may just decide to mostly ignore the Senate race here and focus on the open races for Governor and State Auditor while trying to field a credible challenger for Secretary of State Steve Simon. This would also free up funds for the NRSC to focus on pick ups in more likely places: Indiana, Montana, Missouri, West Virginia, North Dakota & Wisconsin. The NRSC will also have to sure up incumbents in Arizona and Nevada. Pouring money into a race where the incumbent has a 72% approval rating isn't wise when you have so many other places to spend your money and man power more effectively.
All of that being said, who may run for the GOP nomination in 2018? Well, the most credible challenger would be Eric Paulsen. Problem there is that the NRC is going to want to encourage him to stay and defend his 50.8%-41.4% Clinton seat. If Paulsen is looking for a promotion to avoid a tough reelection battle, he may decide to take the plunge and run for Governor. That's really it. No one on the GOP side has even raised the possibility of running. This could change if a prominent Republican starts to take a hold of the Gubernatorial Nomination. If that happens, a member of the State Legislature may be looking to raise his or her profile by running a race that expectations will start so low that anything short of a 35% loss would be considered an improvement over 2012 and expectations for 2018.