The polls aren't national studies, but rather just asking people in a state what they think of their senator. Of the Top 10 senators, seven are either Democrats or Independents who caucus with the Democrats. The remaining three are Republicans.
Bernie Sanders will be happy to get some good news that he is #1, with a lofty 80% approval. In fact, the people of Vermont are especially happy folks, since their other senator, Democrat Patrick Leahy, is #5. Another state -- Minnesota also has both of their senators in the Top 10, both Democrats -- Amy Klobucher who is #7 (at 68% approval) and...yes, Al Franken coming in at #9. (His 63% approval against just 26% negative suggests he's done an impressive job overcoming his image as just a media celebrity, and that he'll likely be there in the senate for a long time, assuming he wants to stay.)
A couple other things struck me as notable concerning the senators in my two states of interest. The first is that in California, a decidedly Blue state, it only gives its two Democrat senators barely passable marks. Both are near-identical. Barbara Boxer's numbers are 51-32% (favorable/unfavorable), and Dianne Feinstein's are 52-32%. I can certainly understand the mediocre results for Sen. Feinstein since she tends to be more moderate-to- conservative than the state is generally, but Boxer's surprise me. The 74-year-old Boxer is retiring, however, and not up for re-election this year, so the matter is reasonably moot. Just surprising.
The other number that stood out to me is for Mark Kirk, the Republican senator from Illinois, who was the second lowest approval in the entire U.S. Senate. His approval is only 39% -- just barely squeaking past Democratic senator Gary Peters of Michigan, who has 38%. (Though with the margin of error, it's possible he could be at the bottom after all.) This stands out because Sen. Kirk is up for re-election in November, and explains why he's considered very vulnerable against Democratic challenger Tammy Baldwin -- even without having Donald Trump likely at the head of the ticket. But I'm also a little surprised his numbers are so low. Even though Illinois is a basically-Blue state, Mr. Kirk is a moderate by today's GOP standards, particularly on social issues. And Illinois has a history of electing Republicans on occasion. The current governor is Republican, for that matter. Then again, the people of Illinois are pretty tough on their elected representatives -- Dick Durbin, the Democratic Senate Whip (a fellow I like and think does a pretty good job) only has a 43% approval, with 26 negative.
Anyway, it's an interesting chart, and worth looking at for your own state's senators, or just to see how things play out across the country with the November elections looming.