There's some truth here, but it's not as dramatic as the 30-second ad portrays.
Rather than supporting a scholarship fund aimed at illegal aliens, Huckabee supported a measure that would have allowed the children of illegal aliens who graduated from Arkansas high schools to receive in-state tuition and apply for a state-funded scholarship program, the Academic Challenge Scholarship. Arkansas students can qualify for the scholarship if they achieve a specific grade-point average (3.0 out of 4.0 for a four-year college) and meet a few other basic criteria.
At a November 2007 debate in St. Petersburg, Huckabee said he supported the measure so that the children of illegal immigrants could have "the same scholarship that their peers had, who had also gone to high school with them and sat in the same classrooms."
(Huckabee also claimed the rules regarding this proposal were stricter than they actually were; we checked that claim here . We also checked previous claims from Romney on similar issues here and here .)
Even though Huckabee supported the measure in 2005, it never made it out of the Arkansas legislature, so it never became a law in Arkansas.
Romney is right in his assertion, but he glosses over a few important caveats to get there. For that reason, we rate this claim Mostly True.