8. The American National Election Studies conducts periodic research on the opinions of U.S. voters. The accompanying table shows the percentage of people, in selected years from 1952 to 2008, who agreed with the statement “There are important differences in what the Republicans and Democrats stand for.”
| Year | Agree with statement |
| 1952 | 50% |
| 1972 | 46 |
| 1992 | 60 |
| 2004 | 76 |
| 2008 | 78 |
|
Data from: American National Election Studies. |
|
What do these data say about the degree of partisanship in U.S. politics over time?