AUGUSTA – Maine voters were deciding more than two dozen primary elections for the Legislature on Tuesday in a prelude to a heated competition between Democrats and Republicans this fall for majorities in the state Senate and House of Representatives.

Once again, the election year is being shaped by Republican vows to rebound and Democratic insistence that they can retain control.

A Democratic winning streak in general elections for the House dates to 1974. Republicans have held the Senate outright for only one two-year period since the 1982 elections.

In 2000, statewide voting left the Senate split 17-17, with one independent.

On Tuesday, there were 11 contested House primaries for each of the two major parties. In the Senate, Democrats faced each other in three districts, while the Republicans had two contested Senate primaries.

Two closely watched Democratic Senate contests were centered in Biddeford and Gardiner.

House Republican showdowns in Augusta, where Rachel Ellis, the wife of the state party chairman, trounced conservative activist Michael Hein by a margin of 3-1 in unofficial returns, and rural towns to the west of the capital had also drawn attention.

In Wells, House District 147 had contested Democratic and Republican primaries.

Kathleen Chase defeated James Spiller in the GOP race, according to unofficial returns, by a vote of 325-238.

Winning Democrats, according to unofficial returns, included Pamela Trinward of Waterville in House District 77, Ted Susi of Norridgewock in House District 86, Paulette Beaudoin of Biddeford in House District 135 and Anthony Cilluffo of Wells in House District 147.

Other apparent Democratic victors included former House member Joe Brooks of Winterport in House District 42, Jane Scease of Topsham in House District 60, Jill Conover of Oakland in House District 78 and Alan Casavant of Biddeford in House District 137.

In the House, Democrats now hold a 74-73 edge over the GOP. The House also has one Green party member and three independents.

The numbers are also close in the Senate, where Democrats have a 19-16 majority over Republicans.

Republicans say they will have candidates in all 151 House districts and all 35 in the Senate. Democrats expect to field candidates for all Senate seats and all House seats except in House District 107, where independent Rep. Richard Woodbury of Yarmouth is seeking re-election.

Following on the heels of state party conventions in Augusta, the elections being held Tuesday were new tests for new leadership teams at both Democratic and Republican headquarters.

Democratic Party Chairman Ben Dudley, a fourth-term state representative from Portland, was chosen to become Democratic chairman in April in the wake of former House Speaker Patrick Colwell’s announcement that he would be stepping down.

Colwell, whose candidacy for the party chairmanship had been encouraged by Gov. John Baldacci, won the job in January 2005 by defeating two other candidates.

Earlier this year, Julie Ann O’Brien, a former four-term legislator from Augusta, took over as executive director of the Maine Republican Party.

O’Brien succeeded Michael Leavitt, who was hired by the Republican National Committee to fill a party leadership post in Maryland.