Another son, Jeb Bush, unsuccessfully sought the Republican presidential nomination in the 2016 Republican primaries. After a long battle with vascular Parkinson's disease, Bush died at his home on November 30, 2018. Historians generally rank Bush as an above average president. In 1964, Bush sought to unseat liberal Democrat Ralph W. Yarborough in Texas's U.S. Senate election. Historians generally rank Bush as an above average president. In 1964, Bush sought to unseat liberal Democrat Ralph W. Yarborough in Texas's U.S. Senate election. Bolstered by superior fundraising, Bush won the Republican primary by defeating former gubernatorial nominee Jack Cox in a run-off election. In the general election, Bush attacked Yarborough's vote for the Civil Rights Act of 1964, which banned racial and gender discrimination in public institutions and in many privately owned businesses.