Why? Gillibrand is obviously the weaker of the two and Treadwell has strong money connections.
Why do you consider Gillibrand the weaker one? Her district is marginally more Republican (they're both Republican leans) but by all accounts she's an extremely gifted politician, tireless with both constituent services and fundraising. I know this makes me sound like one of her staffers, but she has more money on hand than the entire NRCC and Stu Rothenberg called her "impossible not to like."
This is a district where local relationships and supporting the community counts for far more than ideology. Hall's district, by comparison, has more affluent suburbanites who may be more loyal to the Republican party in a presidential year.
Canseco's biggest challenge will be getting past any potential Anglo opponents in the Republican primary.