The political science keywords here I would be looking at are ‘polarization’, ‘slate voting’, ‘split ticket’ and ‘downballot/downticket’. Essentially, how many voters are voting for X solely and completely because X is now their party’s nominee and that’s that, they neither know nor care anything about the candidates, because you simply can’t let the Y party win? Rapid career rises are thought-provoking but too qualitative (who ever heard of Barry Obama before he gave that speech and began his run for president? Or imagine if John McCain had died a few years earlier—who outside Alaska, a tiny state population-wise, not even 0.8m people, had ever heard of Sarah Palin? I sure hadn’t, but unclear what that means). This can be quantified by looking at the increase in straight party voting, and also by natural experiments: obviously, the presidential candidate hasn’t died during campaigning recently so no examples there, but there are a lot of elections out there and many candidates will die or otherwise be incapacitated, and their replacement will be effectively an unknown and probably not all that heavily selected in terms of a political career.
The political science keywords here I would be looking at are ‘polarization’, ‘slate voting’, ‘split ticket’ and ‘downballot/downticket’. Essentially, how many voters are voting for X solely and completely because X is now their party’s nominee and that’s that, they neither know nor care anything about the candidates, because you simply can’t let the Y party win? Rapid career rises are thought-provoking but too qualitative (who ever heard of Barry Obama before he gave that speech and began his run for president? Or imagine if John McCain had died a few years earlier—who outside Alaska, a tiny state population-wise, not even 0.8m people, had ever heard of Sarah Palin? I sure hadn’t, but unclear what that means). This can be quantified by looking at the increase in straight party voting, and also by natural experiments: obviously, the presidential candidate hasn’t died during campaigning recently so no examples there, but there are a lot of elections out there and many candidates will die or otherwise be incapacitated, and their replacement will be effectively an unknown and probably not all that heavily selected in terms of a political career.