By Tiffany Williams –

AUGUSTA, Maine — Maine voters headed to the polls Tuesday to cast ballots in a series of closely watched primary elections that will determine Democratic and Republican nominees for governor, the U.S. Senate and two congressional seats ahead of the November general election.
With 397 of 644 precincts reporting, the Democratic primary for U.S. Senate saw Graham Platner holding a substantial lead over his opponents in the race to challenge Republican Sen. Susan Collins.
Platner received 120,304 votes, or 72.06 percent of the vote. Janet Mills was second with 32,562 votes, representing 19.51 percent, while David Costello received 13,385 votes, or 8.02 percent. Write-in candidate Andrea LaFlamme received 690 votes, accounting for 0.41 percent.
The governor’s race remained one of the most competitive contests on the ballot.
In the Democratic gubernatorial primary, Nirav Shah led the field with 44,745 votes, or 26.6 percent, with 62 percent of precincts reporting.
Hannah Pingree followed with 38,941 votes, or 23.15 percent. Troy Jackson received 35,886 votes, representing 21.33 percent, while Shenna Bellows received 35,013 votes, or 20.81 percent. Angus King III received 13,654 votes, accounting for 8.12 percent.
The Republican gubernatorial primary also featured a crowded field.
Bobby Charles led with 35,112 votes, or 37.86 percent.
Jonathan Bush and Benjamin Midgley were tied with 18,600 votes each, representing 20.05 percent of the vote.
Garrett Mason received 10,301 votes, or 11.11 percent. Owen McCarthy followed with 3,669 votes, representing 3.96 percent. David Jones received 2,915 votes, or 3.14 percent. Robert Wessels received 2,355 votes, accounting for 2.54 percent, while James Libby received 1,194 votes, or 1.29 percent.
Voters were also deciding nominees in Maine’s congressional races.
In the Democratic primary for the 2nd Congressional District, Joseph Baldacci held a narrow lead with 18,018 votes, or 31.67 percent, with 277 of 487 precincts reporting.
Jordan Wood remained close behind with 16,687 votes, representing 29.33 percent. Matthew Dunlap received 16,380 votes, or 28.79 percent, while Paige Loud received 5,800 votes, accounting for 10.2 percent.
The winner of the Democratic primary will advance to the general election to face former Republican Gov. Paul LePage, who is running unopposed for the Republican nomination. The seat is open after Rep. Jared Golden announced earlier this year that he would not seek re-election.
In Maine’s 1st Congressional District Republican primary, Ronald Russell held a narrow advantage over Joshua Pietrowicz.
With 121 of 158 precincts reporting, Russell received 19,665 votes, or 52.72 percent, while Pietrowicz received 17,634 votes, representing 47.28 percent.
A total of 37,299 votes had been counted in the race.
Primary election results remained unofficial Tuesday night as vote counting continued across the state.
The winners of the primary contests will advance to the November general election, where voters will decide races for governor, the U.S. Senate and Maine’s congressional delegation.