Maryland’s ballot-box fight over immigrant tuition essentially moved from courtrooms to campaign building months ago, but opponents on Tuesday made one last legal argument that the state’s Dream Act should be exempt from going before voters in November.

High-powered Democratic lawyers and immigrant rights groups asked Maryland’s highest court to reverse a lower court ruling that the Dream Act – which would give undocumented immigrants in-state college tuition breaks – amounts to a fiscal measure and therefore cannot be petitioned to referendum.

It’s an argument Dream Act supporters lost in February when a Circuit Court judge ruled that Maryland’s legislature intended the law to be a policy change and therefore fiscal effects were “incidental.”

If the lower court ruling stands, Maryland’s ballot is expected to be the lone November proxy in a national debate over the Dream Act. Republican presidential candidate Mitt Romney has forcefully opposed tuition breaks for illegal immigrants while President Obama has backed national Dream Act legislation.

The measure is the first on any topic that has been petitioned to referendum in Maryland in 20 years.

Leading up to Tuesday’s oral argument, few on either side said they expected Maryland’s Court of Appeals to reverse course. Still the court has surprised observers by upending legislative decisions with increasing frequency in the last year, giving opponents of the referendum some hope.

Tuesday is the court’s final day before summer recess. It was unclear how quickly it might rule.

Under Maryland’s Dream Act, undocumented immigrants who can prove that they have attended Maryland high schools for at least three years and whose parents or guardians have filed taxes (but not necessarily earned enough to pay taxes), would be allowed to begin courses at community colleges at in-state rates.

Those who go on to earn an associate’s degree could transfer to a four-year institution at in-state rates. At the University of Maryland, annual tuition and fees for in-state students is $8,655, compared with $26,026 for out-of-state students.

Two unnamed illegal immigrants who have graduated from Maryland high schools are among plaintiffs in the suit. In court filings, they have said they could not afford out-of-state tuition rates.

Maryland’s legislature approved the Dream Act legislation last April, after years of failed attempts.

At the time, Republicans who argued against the bill said it amounted to a spending measure – an objection party leaders routinely make to criticize Maryland Democrats for not fully assessing fiscal impacts of policy decisions.

Ironically, the conservative group Judicial Watch, which has represented referendum proponents in court, argues the measure is a policy decision. Joseph Sandler, former general counsel for the Democratic National Committee, has maintained the law is a fiscal issue and therefore exempt from second guessing by voters.