Polling numbers in crucial swing states and voter demographics are among the top considerations Pimco's Libby Cantrill is using to predict a 70 to 75 percent chance of a Hillary Clinton win, the analyst said Tuesday.

"We're looking at the polling in these crucial swing states of Ohio, of Florida, of North Carolina and of Pennsylvania," Cantrill, executive vice president and head of public policy at the firm, told CNBC.

"Because of Donald Trump's more narrow path to the 270 electoral votes that he needs to get to win the White House, he has to win North Carolina, he has to win Florida, he has to win Ohio," she said.

Cantrill told "Squawk Box" that Clinton's edge in North Carolina, where the race is in a dead heat, comes from early voting among Hispanics and women.

And overall, Cantrill said there are broader tail winds pushing the Clinton campaign closer to victory.

"If you look at the polling in those swing states, if you look at the demographic shifts that are definitely in Democrats' favor, if you look at the underlying fundamentals of the economy, if you look at [Barack] Obama's positive approval rating," Cantrill said odds seem to be in the Democratic candidate's favor.