In paragraph 16-18 the story Randy and Cherie is used as evidence for what claim

The stories of Randy and Cherie's experience of losing their jobs and having difficulty finding further well paid employment is used as evidence the American Dream is getting harder to reach.

Explanation:

Randy and Cherie are former TWA flight attendants. They lost their employment and a lot of their potential benefits like pensions that were furloughed in the takeover of TWA by American Airlines in 2001. The husband and wife have both had trouble finding new work that pays well. They work low wage jobs of 9 and 7.25 an hour. They have had to downsize their home and budget significantly. The author David Wallechinsky uses this and other examples as evidence that the American Dream is getting harder and harder to obtain for many families.