Attorney General Douglas F. Gansler recommended today that about 50,000 Maryland 17-year-olds be allowed to vote in the Feb. 12 presidential primary, reversing an opinion from his staff that prompted state officials to deny them voting rights before they are 18.

The First Amendment right of the state's political parties to determine who can vote in primary elections trumps any new state policy on voter-age restrictions, Gansler said in a five-page opinion his office issued this morning.

Since the 1970s, Maryland residents have been able to register at age 17 as long as they turned 18 by the date of the general election in November. Tens of thousands of 17-year-olds routinely voted in primary elections.

But the Board of Elections reversed the policy late last year, based on an opinion from the attorney general's office. A state lawyer advised election officials that a December 2006 Court of Appeals decision invalidating an early-voting law passed by the General Assembly that year also affected voters in primary elections. Assistant Attorney General Mark Davis wrote that primaries, according to the court's ruling, are governed by the same regulations as general elections, which allow only those 18 and over to vote.

But the change in policy drew protests from the state Republican and Democratic parties, which have an interest in seeing as many new voters on the rolls as possible. The parties heard complaints from angry parents and their teenagers.

The issue also galvanized voting-rights advocates, who complained that confusion over the new rules led to very low registration by 17-year-olds this year. Students at Archbishop Spalding School in Severn launched a page on Facebook to protest the ruling and prepared to come to Annapolis to protest.

On Monday, Sen. Jamie B. Raskin (D-Montgomery) asked Gansler for a formal opinion on whether Maryland's political parties could decide the question. Raskin, a law professor who has taken an interest in voting-rights issues in the legislature, argued that the parties' federal right to freedom of association to determine who can participate in choosing the party's candidates for office overruled any interpretation of state law.

Gansler agreed with Raskin today and recommended that the Board of Elections change its policy. At a meeting tomorrow, the board is expected to reinstate the right of 17-year-olds to vote in next month's Democratic and Republican primaries.

Timing of the change will be tight, though: Jan. 22 is the registration deadline to vote in the primary.

Raskin said that in spite of the confusion so close the primary, the controversy may result in more interest by young voters in participating in the political process.

FairVote, a voting rights group, this morning announced a public information campaign with the Maryland Association of Secondary School Principals to notify eligible students of the registration deadline.