The Gallup poll showed Americans aged 65 and older moved from reliably Democratic supporters to Republicans supporters between 1992 and 2012. The Gallup story cites race as a primary factor because older Americans are predominantly non-Hispanic whites while younger age groups of Americans are more racially diverse and tend to support Democrats.
Whatever the reason for the shift, Gallup's contention that yesterday's Democrats support today's Republicans jibes with a Democracy Campaign finding in 2011. A review of campaign contributions from retirees to candidates for governor and the legislature from 1993 through 2010 showed parity between Republican and Democratic candidates early on, and then a sharp shift to Republican candidates since the 2006 election cycle.
An updated Democracy Campaign analysis of large campaign contributions - those who contributed $100 or more in a year - from retirees by decade found this: