The former Massachusetts governor told CNN's Jake Tapper on "The Lead," the strategy "is to peel off Republican votes from Donald Trump."
Weld's partnership with his running mate at the top of the ticket, Gary Johnson, has failed to break out thus far in the election. Low polling has kept them off the official debate stages, and Johnson's multiple, high-profile foreign policy gaffes on live television have furthered dampened their outlook.
Weld also said concerns that the Libertarian ticket is hurting Democratic nominee Hillary Clinton with millennials has prompted a liberal backlash.
"I'm certainly getting a lot of free legal advice from Democrats -- some who I know, and some who I don't know -- who are sending me emails and telephone calls at private numbers who are saying, 'You've got to get off the ticket. You'll be a disgrace. It'll be a shame on your family if Trump is elected.' But that's just because they don't want to have millennial votes peeled off from Mrs. Clinton," Weld said.
He also tried to make the case that despite Johnson's appeal to some young voters, their real success was with Republicans.
"I like to go hunting where the ducks are," Weld said. "I think there's more ducks to be hunted on the Republican side of the aisle."
Weld attributed the ticket's performance with young voters to a desire for personal independence.
"They want to make choices in their own lives, and that's a really resonant message," Weld said.
The former Massachusetts governor has called Hillary Clinton a friend, and President Bill Clinton once tapped him to be the US ambassador to Mexico, before he had to pull out due to pushback from conservative Republicans.
Weld already has not pulled punches against Trump, repeatedly comparing
the Republican nominee's rise to that of the Nazis.
And despite Johnson's recent high-profile stumbles, Weld called him a good, "humble" man.
"Don't laugh, he kind of reminds me in many ways of Abraham Lincoln who was another great truth-teller of his time," Weld said.