It's still too early to call ... but it looks like Roseanne will NOT be the next President of the United States ... and her ex-husband Tom Arnold is partly to blame.
Of course, Roseanne claims to be a serious candidate to be the next leader of the free world ... running as the nominee of the Peace and Freedom Party.
In case you haven't followed her campaign, here's a summary -- she hates both Democrats and Republicans and REAAALLLLLY wants to legalize marijuana. That's pretty much it.
But her ex-hubby Tom Arnold tells TMZ ... she just hasn't earned his vote -- saying, "I'm voting for Obama, but for God's sake let Roseanne have her pot ... she's 60."
REMINDER -- Don't forget to vote today ... or Sophia Bush will be ashamed of you.
6:30 AM PT -- Roseanne isn't getting much help from her old castmates either.
We spoke to Michael Fishman -- who played DJ on "Roseanne" -- who tells us, "[Obama] is a very qualified choice."