Jim says his brother, William, is a Democrat who voted for Mondale. Former Vice President Walter Mondale was the unpopular Democratic opponent to Ronald Reagan in 1984. Nationally, Reagan won the popular vote 58.8% to 40.6%, while in Texas, it was 63.6% to 36.1%, illustrating a clear preference for Reagan in 1984 Texas. No other presidential election in the state has seen a winner by that much since then, as of 2020.
When Georgie and Mandy get married, Missy says that Georgie is her only brother and later says that she wouldn't invite Sheldon to her wedding. While it is not known if that happened or not, both Georgie and Missy attended Sheldon's wedding in The Big Bang Theory (2007).
Lyndon, the man who married Georgie and Mandy, is more than likely named after (Democratic) President Lyndon B. Johnson, a native of Texas.