If you read past the sensational headline, you'll see that Rubio is actually pro-legalization of online poker, but is just against legalizing other forms of online gambling.
He isn't a fan of the current state-by-state regulation and would prefer to do it federally, but it basically sounds like he wants to leave online poker alone, even though Adelson (who has expressed interest in backing him) is against online poker.
So that's good enough.
I wouldn't vote for the guy if he was a rabid online poker opponent, but since he's already qualifying that online poker is different and he'd be fine with regulation of it, I can feel fine about supporting him.