AUGUSTA — Republicans and Democrats were miles apart when they started congressional redistricting but ended up with a bipartisan plan two years ago. Both sides will see if they can come to terms again as they begin an even bigger process of redrawing Maine’s 186 House and Senate district lines.

A 15-member commission comprised mostly of Democratic and Republican legislators and party leaders got to work Friday to sort out timetables and criteria for their work through the winter and spring.

Chairman Michael Friedman said he’s optimistic that members will work together, but that’s not always the case in other states where the redistricting process can become highly politicized, leading to gridlock and legal battles.

“I haven’t seen any posturing at all. I’m encouraged,” said Friedman, a Bangor attorney and political independent who also led the congressional reapportionment panel.

The Maine Constitution requires redistricting every 10 years following the census to ensure that state legislative districts reflect population shifts.

The redistricting panel must issue its report by June 1, and the Legislature must act by June 11. If it fails to do so, the Supreme Judicial Court must do the job.

Two years ago, Republicans and Democrats came to the table with vastly different congressional redistricting proposals, with the GOP proposing to drastically redraw the districts.

In the end, both sides agreed on a compromise plan, and the proposal won House and Senate passage with virtually no opposition. Waterville and Winslow became part of the 1st District and Lewiston and Auburn remained in the 2nd District. Eleven other municipalities were affected.

A constitutional amendment approved by Maine voters months later now mandates a two-thirds vote by lawmakers, making compromise a necessity, Friedman said.

The amendment also put the state in sync with the rest of the country by starting the process after each census. The next redistricting will happen in 2021.

The process now under way is seemingly more complicated because there are so many lines to be redrawn, with 151 House districts and 35 Senate districts. On top of that, districts must be redrawn for 48 county commissioners, three from each of the state’s 16 counties.

The commission on Friday adopted the criteria it will use, including giving preference to districts that have near equal populations, are compact and contiguous, cross as few municipal lines as possible, and preserve existing district boundaries if possible.

A decade ago, the Legislature agreed on a remapping plan for the state House of Representatives. But when lawmakers couldn’t agree on new district lines for the Senate, the matter went to the state Supreme Court, which ultimately decided the final Senate map.

This time around, both Democratic and Republican commission members said they’ll be striving to reach agreement on the maps without going to the state’s highest court. The parties don’t have to publicly present any of their proposed redistricting maps until March.

“Our goal is to do things by consensus as much as possible,” said Maine Democratic Party chairman Ben Grant. “But we’re also realistic about what’s at stake in this process.”

Josh Tardy, a former GOP legislative leader who’s on the commission, said reaching agreement is preferable to “going through the expense and uncertainty that can come from the court exercising its jurisdiction.”

Historically, the process of remapping legislative districts has been less complicated than congressional districts, Friedman said.

Friedman won the thankless job of leading the process because he’s politically independent and because he had a reputation for fairness during two terms on the state ethics commission. “I’ve taken (both parties) to the woodshed a few times,” he said.