Notice that all Republican "rising stars" this century have been massive duds?

[Antonio the Sixth]

Most "rising stars" are.

[Antonio the Sixth]

In politics like most organizations the hierarchy is a pyramid with far more spots near the base than near the peak. Presumably a rising star is recognized when they've moved up from the base but not to the peak. The statistics alone suggest that most such people will never find the timing or opportunity to find a place in the upper ranks. So most rising stars will necessarily end up as duds if judged by how high they might have been expected to rise if everything worked to their advantage.

This.

[Antonio the Sixth]

I'd consider Nixon a rising star, given his quick g to political prominence while and Congress and being picked for VP after with less than 2 years as Senator.

True, but he certainly wasn't a 'rising star' when he was elected, and one could argue that he was a dud as well, considering how his presidency ended.

He would definitely have been seen as a dud from 1962 to 1967.