Donald Trump's Possible Paths to Victory

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

— -- Donald Trump's path to victory isn't clear and isn't set, but the Republican presidential nominee and his team have been working to ensure he has multiple paths to reach the 270 electoral votes needed to win.

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.

Trump campaign manager Kellyanne Conway said on "Good Morning America" today that winning one of those states would be a tipping point for a Trump victory.

"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.

The Sunshine State is something of a golden ticket for each of the presidential candidates, in that winning Florida's 29 Electoral College votes makes the other's path to victory far more difficult.

In Trump's case, if Clinton wins Florida, he could still get to 270 electoral votes by winning in Michigan, Wisconsin and Pennsylvania. But if he loses Florida and Pennsylvania, he will have to win Nevada, Iowa and Colorado to make up for it. That all has to happen with Trump holding on to North Carolina and Georgia — which GOP nominee Mitt Romney won in 2012 — and taking Ohio.

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 political analyst Matthew Dowd compared the presidential race at this point to the tail end of the New York City Marathon, the annual road race that was held Sunday.

"Hillary Clinton is about 4 miles ahead in the 25th mile of the New York Marathon. Can Donald Trump still win? Yeah, but she would actually not only stop running, she would have to walk, and she would probably have to fall down if she’s going to lose at this point,” Dowd said.

ABC News' Ryan Struyk contributed to this report.