Donald Trump's Possible Paths to Victory

He's been trying to build multiple ways to reach 270 electoral votes.

One route he has been working toward includes Wisconsin, Minnesota and Michigan. Of the three, Michigan was the most recent to vote Republican, but that was back in 1988.

"It would be one of those Upper Midwest states — like a Michigan or Wisconsin, Minnesota — and/or one of those Rocky Mountain states. So we've had our eye for a while on bringing back these states that have voted Republican in the nonpresidential years and where the poll numbers have been tightening and where we've at least been able to be semicompetitive on the air and on the ground with the Clinton campaign," she said.

Two key states not mentioned by Conway — Florida and Pennsylvania — are going to be factors as well.

But a lot of variables are at play in these possible routes: Nevada is expected to go blue, as is Colorado, and close races are expected in New Hampshire, North Carolina and the perpetual swing state of Ohio.

ABC News' Ryan Struyk contributed to this report.