Square, gedolim say nowadays not to hate people who aren’t frum. It’s a chidush, because chazal say it’s a Mitzvah to hate unrepretent continual sinners, but naniach.
Hating a reform jew who, for instance, is a proud marcher in the abomination parade, and a member of women of the wall, etc…is definitely not baseless! Whether or not you should depends on who you ask. Im not on the madrega to hate someone leshem shomayim, so I don’t.