New York: Bill Bradley, the former Democratic senator from New Jersey and a long-time vociferous critic of super PACs, has formed just such a group to go after Donald Trump in the final weeks before Election Day with a TV ad that invokes one of the most powerful political attacks in American history.

In September 1964, Lyndon B. Johnson's presidential campaign released "Daisy," a 60-second television advertisement that juxtaposed a petal-picking child with images of nuclear obliteration to caution against a Barry Goldwater presidency. It aired only once, but is widely remembered as perhaps the most powerfully negative TV ad ever created.

Republican presidential candidate Donald Trump speaks during a meeting with local farmers in Florida. Credit:AP

Now a half-century later, adding another peculiar footnote to an unpredictable election cycle, Bradley's new super PAC, 52nd Street Fund, is using similar apocalyptic footage in its first - and likely only - ad buy of the 2016 presidential cycle. According to a person familiar with the plan, the one-week campaign started Monday in Ohio, a must-win state for Trump, targeting voters in the Columbus, Toledo, and Cincinnati media markets.