I AM a genetic Republican.

Five generations of Tafts have served our nation as unwaveringly stalwart Republicans, from Alphonso Taft, who served as attorney general in the late 19th century, through William Howard Taft, who not only was the only person to be both president of the United States and chief justice of the United States but also served as the chief civil administrator of the Philippines and secretary of war, to my cousin, Robert Taft, a two-term governor of Ohio.

As I write, a photograph of my grandfather, Senator Robert Alphonso Taft, looks across at me from the wall of my office. He led the Republican Party in the United States Senate in the 1940s and early 1950s, ran for the Republican nomination for president three times and was known as “Mr. Republican.” If he were alive today, I can assure you he wouldn’t even recognize the modern Republican Party, which has repeatedly brought the United States of America to the edge of a fiscal cliff — seemingly with every intention of pushing us off the edge.

Throughout my family’s more than 170-year legacy of public service, Republicans have represented the voice of fiscal conservatism. Republicans have been the adults in the room. Yet somehow the current generation of party activists has managed to do what no previous Republicans have been able to do — position the Democratic Party as the agents of fiscal responsibility.

Speaking through the night, Senator Ted Cruz, with heavy-lidded, sleep-deprived eyes, conveyed not the libertarian element in Republican philosophy that advocates for smaller government and less intrusion into the personal lives of citizens, but a new, virulent strain of empty nihilism: “blow it up if we can’t get what we want.”