No, I think most political analysts as well most people on this forum severely overestimate the impact of a candidate on voters choices, since 1988, with the exception of 2008 which was a unique year, no party has exceeded 51.1% of the vote, most voters, over 90% are locked in with 90% of dems and GOP's voters respectively always voting for their party no matter the candidate. Of far greater importance are the structural trends underway in the electorate, post grad whites moving towards the dems, high school grad whites moving towards the gop etc.
In that environment, I think no republican would have won Virginia, someone like Rubio maybe does better in NOVA, but can he overcome a 200k margin, I doubt it. Even combining Romney's numbers in NOVA plus Trump's numbers in the rest of the state does not make up the margin.
Would college grads have trended towards the Dems if someone like Rubio was the nominee though? There wasn't a huge swing with college grads from 1992 to 2012. Based on
this (I calculated the numbers with college grads myself by combining postgrads and college grads only) this is how college grads voted (vs the general populace):
1992: 39% Bush (37% Bush)
1996: 44% Dole (40% Dole)
2000: 48% Bush (48% Bush)
2004: 49% Bush (51% Bush)
2008: 45% McCain (46% McCain)
2012: 48% Romney (47% Romney)
2016: 42% Trump (46% Trump)
The swing in the 2000s and early 2010s (pre-Trump) was quite small. This doesn't really stroke with most county-level data (high-income/high-educated counties did shift to the Dems by quite a big margin). Maybe the reason behind that is that those counties often are urbanizing, have become more diverse or have higher proportions of tech workers or federal employees (or other 'creative workers' who might benefit from more government) while college-educated voters in exurban or rural counties have shifted R. I imagine Rubio would have done roughly the same with college-educated voters as other candidates in the 2000s and 2010s, and maybe he would appeal more to urban voters (both whites and minorities) enough to narrowly win Virginia in 2016 if he wins the PV by atleast 2%. But I think it's pretty much lost to the GOP after 2016 (barring landslides or unforseen changes in electoral coalitions).
But if Romney's margins in NoVa and Trump's margins in the rest of Virginia aren't enough to win maybe you're right. If the Republicans want to win Virginia they probably should focus on NoVa, even though that might be futile too (and focusing on NoVa to win Virginia implies not contesting Michigan or those rust belt places that swung hard to Trump).