You stated that Clarence had family in Shelby County, Tennessee, so I did a search there. What I found could possibly be your Clarence. Was he living a double life if it is him? If so, I wonder if he divorced his first wife.

1910 Census - Tennessee
Name: Clarence F Rule
Age in 1910: 22
Estimated birth year: abt 1888
Birthplace: Tennessee
Relation to Head of House: Son
Father's Name: Burgelia Baily
Father's Birth Place: Tennessee
Mother's Name: Sarah Baily
Mother's Birth Place: Tennessee
Home in 1910: Barnitz, Custer, Oklahoma
Marital Status: Married
Race: White
Gender: Male
Household Members:
Name Age
Burgelia Baily 71
Sarah Baily 62
Solon Baily 23
Pearl Rule 18
Clarene F Rule 22

1930 Census - Tennessee
Name: Clarence A Rule
Home in 1930: Memphis, Shelby, Tennessee
Age: 31
Estimated birth year: abt 1899
Birthplace: Kentucky
Relation to Head of House: Head
Spouse's name: Rena H Rule
Race: White
Household Members:
Name Age
Clarence A Rule 31
Rena H Rule 31
Clarence A Rule 6
William A Rule 4
Helen L Rule 1
In this census, there are neighbors with the last name Rule.
Difficult to read the names, but here goes:
Rule, Elius male, head b. KY Occupation, butcher grocery store
Rule, Annette or Amette - female, wife

In the 1930 Census, there is a son also named Clarence born approx. 1924
I found the following which is most likely Clarence Jr.
U.S. Veterans Gravesites, ca.1775-2006 about Clarence A Rule
Name: Clarence A Rule
Service Info.: PFC US ARMY
Birth Date: 22 Apr 1924
Death Date: 4 Jan 1999
Cemetery: Memorial Park Cemetery
Cemetery Address: 5668 Poplar Avenue Memphis, TN 38119

Further searching, I found a SSN death index for Clarence Rule, died in Tennessee, most likely the Clarence Rule in the above census.
Social Security Death Index
Name: Clarence Rule
SSN: 412-07-9462
Last Residence: 38122 Memphis, Shelby, Tennessee, United States of America
Born: 10 Aug 1899
Died: Oct 1973
State (Year) SSN issued: Tennessee (Before 1951)

Now, try this website. You have to have patience to search through the databases, some of the handwriting is difficult to read. http://register.shelby.tn.us/index.php
According to the 1930 census, Clarence was 23, so I believe he and Rena married around 1920, but I don't know where, they weren't listed in the Shelby county marriage index, that I could tell anyway, you may want to search as well.

I hope I am in the right direction with this, I would have to send you in the wrong direction.