The most recent Star Tribune poll, conducted between April 24 and 26, asked registered Minnesota voters if they approve or disapprove of the job performances of senators Amy Klobuchar and Al Franken. Here's what they said:
  

About the poll

This poll was conducted by Mason-Dixon Polling & Research, Inc. of Jacksonville, Florida from April 24 through April 26, 2017. A total of 800 registered Minnesota voters were interviewed statewide by telephone.  
 
Those interviewed on land-lines were selected by the random variation of the last four digits of telephone numbers.  A cross-section of exchanges was utilized in order to ensure an accurate reflection of the state. Those interviewed on cell phones were selected from a list of working cell phone numbers.  Quotas were assigned to reflect voter registration by county.
 
The margin for error, according to standards customarily used by statisticians, is no more than ± 3.5 percentage points.  This means that there is a 95 percent probability that the "true" figure would fall within that range if all adults were surveyed.  The margin for error is higher for any subgroup, such as a gender or age grouping.
 

Demographic breakdown of polling sample

In the last presidential election, did you vote for Donald Trump, Hillary Clinton, a different candidate, or did you not vote in that election?

Trump   270 (34%)
Clinton   299 (37%)
Other/Refused   66 (8%)
Did Not Vote   165 (21%)

In terms of your political party identification, do you generally consider yourself DFL or Democrat, Republican or an independent?

DFL/Democrat   277 (35%)
Republican   264 (33%)
Independent/Other   259 (32%)
AGE:    
18-34   149 (19%)
35-49   247 (31%)
50-64   240 (30%)
65+   161 (20%)
Refused   3 -
INCOME:    
<$25,000   89 (11%)
$25,000-$49,999   144 (18%)
$50,000-$74,999   162 (20%)
$75,000-$99,999   118 (15%)
$100,000+   120 (15%)
Refused   167 (21%)
GENDER:    
Male   387 (48%)
Female   413 (52%)
REGION:    
Hennepin/Ramsey   260 (33%)
Metro Suburbs   230 (29%)
Southern Minnesota   160 (20%)
Northern Minnesota   150 (19%)
INTERVIEW:    
Land-line   554 (69%)
Cell Phone   246 (31%)