AUGUSTA — The legislative commission charged with redrawing Maine’s congressional boundaries on Tuesday voted 8-7 to support a Democratic proposal that pushes additional towns in Kennebec County into the 2nd Congressional District.

Michael Friedman, the lone independent on the commission and chairman of the panel, cast the deciding vote, arguing in part that the Democratic plan kept Androscoggin County in the 2nd District and moved the fewest people.

But that plan could face long odds for enactment.

Republicans on the commission reiterated their willingness to use their legislative majorities in the Legislature to push through their preferred proposal — a more radical plan that would divide Maine east and west — on a straight party-line vote when lawmakers convene for a special session in late September. Doing so would circumvent the Legislature’s statutory two-thirds majority provision currently required to pass a redistricting plan.

Democrats said such a move would prompt them to file a court challenge and potentially mount a people’s veto effort to overturn the GOP plan.

Right now that plan is the GOP’s first proposal, the so-called “Western Maine” map that pushes Androscoggin and Oxford County, along with portions of Franklin County, into the 1st Congressional District with Portland and southern Maine for the first time in 50 years.

The GOP plan also moves 360,000 residents and 139 municipalities into a new congressional district.

Some Republicans in the tri-county area have expressed reluctance to support that plan, but those same lawmakers could face pressure from leadership to toe the party line.

On Tuesday Republicans again said they attempted to offer compromise proposals and that Democrats rejected them. Only one of their alternative proposals has been made public. It too moved Androscoggin County into the 1st District, a move that Democrats said Tuesday was a deal-breaker.

The second GOP proposal, which would have kept Androscoggin County in the 2nd District, was pulled from consideration last week by GOP negotiators because, they said, Democrats objected to moving Waterville into the 1st District, a move that could hurt 2nd District U.S. Rep. Mike Michaud, D-Maine, in 2012.

Democrats, who offered two of their own alternatives to their original plan, insisted they were willing to compromise on the second GOP proposal.

Nonetheless, GOP members on the commission declined to reintroduce the second plan. And, after Tuesday’s 8-7 vote, the GOP withdrew a third plan it made public last Friday.

Instead the Republican commission members advanced their original proposal as the panel’s minority report.

Afterward Rep. Kenneth Fredette, R-Newport, told reporters his party was still willing to negotiate. However, it’s unclear how such talks can proceed now that the GOP has returned to a plan that Democrats have unilaterally rejected.

The GOP’s “Western Maine” proposal divides the state into east and west, a sharp departure from the north-south boundary that has existed since the 1950s when Maine’s congressional district contracted from three districts to two. It also moves North Haven, the hometown of 1st District U.S. Rep. Chellie Pingree, D-Maine, into the 2nd District.

Dan Billings, Gov. Paul LePage’s chief legal counsel, said after the vote that it was likely that Republicans would circumvent the two-thirds provision, as Democrats had done on non-redistricting issues when the party controlled both chambers.

“The reality is that statutes don’t bind the Legislature,” Billings said. “If on Sept. 27 Republicans are united behind a proposal, it has the votes to enact it into law. It seems that throughout this process Democrats have not faced that reality.”

The two-thirds provision was put in place to force both parties to formulate a consensus map. Such a consensus has proven elusive several times in the past, including 2003, when the Maine Supreme Court was forced to be the final arbiter on the district boundary in place today because of the stalemate.

This time, the court would be addressing a different issue if Democrats contest the GOP’s use of their majority to pass their preferred plan without a two-thirds vote. A court challenge by Democrats would have to prove that the GOP plan doesn’t satisfy the redistricting requirements set forth in a previous court decision, which ordered the Legislature to redraw the districts to balance population differences.

The GOP plan and the Democratic plan both yield a population deviation of one additional person in their proposed 2nd Districts.

Republicans are confident their plan would survive a court challenge because legislative decisions often carry more weight with judges.

While Democrats could face an uphill legal battle, the party vowed to also take its case to the court of public opinion and, if necessary, to the voters via a people’s veto effort.

“If they try to change the law (requiring a two-thirds vote of the Legislature to prevail) we will oppose that every step of the way,” Sen. Phil Bartlett, D-Gorham.

Bartlett was also quick to point out that if Republicans circumvent the two-thirds provision in September, the GOP will run the risk of contradicting its unanimous support for LD 494 last session. That resolution, sponsored by Republican lawmaker Dennis Keschl of Belgrade, proposed creating a constitutional amendment that would require a two-thirds vote by the Legislature to approve redistricting plans.

The current two-thirds provision is only written in statute, which is why Republicans could work around it. Future majority parties would not be able to do so if it became part of the state’s Constitution, which is what LD 494 proposed and what was supported by both parties last session.

“We just passed a constitutional amendment to be put to the people that would enshrine the two-thirds vote in the constitution,” Bartlett said. “For them (Republicans) to now turn around and change that, to us, is very hypocritical. Secondly, if they do that, it’s a change in the law and that could be subject to a citizen’s veto.”

He added, “We’re simply not going to let them push us around by changing the law.”

If Republicans are successful advancing their plan, the Lewiston-Auburn region would share the same congressional district as Portland. Like the partisan debate in Augusta, it appears that opinions about whether or not that’s a good idea depends on party affiliation.

Lewiston Mayor Larry Gilbert, a Democrat, testified against the move during last week’s public hearing. He argued that the GOP plan would break up longstanding tri-county alliances and put the region in Portland’s shadow.

Jonathan LaBonte, a conservative running for Auburn mayor, said the GOP plan was “brilliant” not because of political considerations, but because it aligned Portland and L-A’s shared policy interests, including a shared transportation corridor along I-95.

“The party establishments have pushed us into a political fight, but there could be a good conversation over the practical benefits,” LaBonte said.

Chip Morrison, executive director of the Androscoggin County Chamber of Commerce, said his organization wouldn’t take a position on redistricting. However, Morrison said the rhetoric was all about attaining a political advantage.

“Watching all the partisan wrangling over this makes me want to throw up,” he said. “Both sides are trying to make rational arguments for political decisions. It’s disgusting.”

Democrats have described the recent attempt as “Raye-districting.” That’s because moving Androscoggin County presumably would increase the chances for Senate President Kevin Raye, R-Perry, to defeat Michaud in 2012 if he runs for the congressional seat.

Republicans have countered that Democrats are only interested in protecting their incumbents in 2012.

The remapping process could also factor into the 2012 presidential race. Maine has four electoral votes in the Electoral College, but it divvies up its electoral votes differently than most states.

Maine is one of two states that award electoral votes through the Congressional District Method, distributing electoral votes based on the popular vote winner within each congressional district. The winner of the statewide popular vote receives two additional electoral votes.

In recent presidential elections, Maine’s electoral votes have gone to Democratic presidential candidates. However, that dynamic could change in 2012 if the GOP is successful in making the 2nd District a Republican stronghold.

Billings, with the governor’s office, rejected some Democrats’ claims that the national Republican Party drafted the Maine GOP’s original redistricting plan to give the GOP presidential hopeful a leg up in Maine in 2012.

“I don’t think anyone on the commission has been in contact with anyone from Washington,” Billings said. “That’s a Democrat talking point to make it seem like we’re being pushed by people in Washington.”