Half-cousins to George H.W. Bush?

The following information was provided by A. Wayne Babcock.

Descendants of Samuel Bullock and Mary Thurber (daughter of John and Priscilla) evidently have former U.S. President George H. W. Bush as a half-cousin, as Thankful Bullock, daughter of Samuel Bullock and 2nd wife Thankful Rouse (or Ropuse or Reneff) appears to be an ancestor of the former President:

Richard Bullock (1622-1667) & Elizabeth Ingraham
Samuel Bullock* (1648-1717) & Mary Thurber (1656-1674)
Samuel Bullock* (1648-1717) & Thankful Rouse/Ropuse/Renneff
Thankful Bullock (1681-1762) & Ephraim Martin (1675-1733)
Lydia Martin (1718-1798) & Rev. Nathan Pierce (1715-1793)
Isaac Pierce (1763-1849) & Anna Fitch (1763-1809)
Levi Pierce (1797-1838) & Betsey S Wheeler (1800-1881)
Elizabeth Slade Pierce (1822-1901) & Courtland Philip Livingston Butler (1813-1891)
Mary Elizabeth Butler (1850-1897) & Robert Emmet Sheldon (1845-1917)
Flora Sheldon (1872-1920) & Samuel Prescott Bush (1863-1948)
Prescott Sheldon Bush (1895-1972) & Dorothy Walker (1901-)
George Herbert Walker Bush (1924-) & Barbara Pierce (1925-)

source: Gedcom file for US President George H.W. Bush provided by ROOTS-L Resources -- Historical Names and Families.