Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| District | Incumbent | Party | First elected | Result | Candidates |
| --- | --- | --- | --- | --- | --- |
| Texas 1 | Wright Patman | Democratic | 1928.0 | Re-elected | Wright Patman (D) 98.8% Joe C. Hailey (R) 1.2% |
| Texas 2 | Martin Dies, Jr. | Democratic | 1930.0 | Re-elected | Martin Dies, Jr. (D) Unopposed |
| Texas 3 | Morgan G. Sanders | Democratic | 1920.0 | Lost renomination Democratic hold | Lindley Beckworth (D) Unopposed |
| Texas 4 | Sam Rayburn | Democratic | 1912.0 | Re-elected | Sam Rayburn (D) 97.9% Ross E. Johnson (R) 2.1% |
| Texas 6 | Luther A. Johnson | Democratic | 1922.0 | Re-elected | Luther A. Johnson (D) Unopposed |
| Texas 7 | Nat Patton | Democratic | 1934.0 | Re-elected | Nat Patton (D) Unopposed |
| Texas 9 | Joseph J. Mansfield | Democratic | 1916.0 | Re-elected | Joseph J. Mansfield (D) Unopposed |
| Texas 10 | Lyndon B. Johnson | Democratic | 1937.0 | Re-elected | Lyndon B. Johnson (D) Unopposed |
| Texas 11 | William R. Poage | Democratic | 1936.0 | Re-elected | William R. Poage (D) 98.6% D. E. Wooley (R) 1.4% |
| Texas 12 | Fritz G. Lanham | Democratic | 1919.0 | Re-elected | Fritz G. Lanham (D) Unopposed |
| Texas 13 | William D. McFarlane | Democratic | 1932.0 | Lost renomination Democratic hold | Ed Gossett (D) 98.6% Adolph Lohman (R) 1.4% |
| Texas 14 | Richard M. Kleberg | Democratic | 1931.0 | Re-elected | Richard M. Kleberg (D) Unopposed |
| Texas 15 | Milton H. West | Democratic | 1933.0 | Re-elected | Milton H. West (D) Unopposed |
| Texas 16 | R. Ewing Thomason | Democratic | 1930.0 | Re-elected | R. Ewing Thomason (D) Unopposed |
| Texas 17 | Clyde L. Garrett | Democratic | 1936.0 | Re-elected | Clyde L. Garrett (D) Unopposed |
| Texas 18 | John Marvin Jones | Democratic | 1916.0 | Re-elected | John Marvin Jones (D) Unopposed |
| Texas 19 | George H. Mahon | Democratic | 1934.0 | Re-elected | George H. Mahon (D) Unopposed |
Question:
Who are all the candidates when Sam Rayburn was incumbent?
Answer:
Sam Rayburn (D) 97.9% Ross E. Johnson (R) 2.1%