Corrected for "the calendar," Mittens running 4-6% better than McCain in 2008

[Mr. Morden]

At least one data point is wrong - Romney only got 28% in Tennessee, not 38%.

But, yeah, I think that makes sense. Both Romney and McCain were weak frontrunners.

You can't really compare Romney and McCain here. Romney has never not been considered the frontrunner. McCain had made a major comeback to win most of the early states.

I think that going into NH, Romney was considered the frontrunner in reality.  After NH, he lost that status.

Giuliani was the frontrunner before McCain. Romney was actually polling fourth place nationally throughout the first two weeks of 2008 (source)

Depends on what you mean by "frontrunner".  For people who actually believed that national polls could predict the winner, Giuliani was the frontrunner.  But people who thought that the early states would be decisive regarded Romney as the frontrunner.  Romney was the consensus favorite here on Atlas throughout the second half of 2007:

https://uselectionatlas.org/FORUM/index.php?topic=67110.0