HARRISBURG, Pa. — There are a few signs of progress, a week into the three-week period established by the state Supreme Court for lawmakers to produce a replacement congressional district map.

Senate Republican leaders introduced a bill Monday that could become legislation to replace the 18-district map ruled unconstitutional by the Supreme Court last week, but they say a lack of guidance from the justices is a problem.

The high court threw out the existing maps but has not issued a full opinion laying out the reasoning in detail. The court majority said in its brief order that the replacement districts must be “composed of compact and contiguous territory, as nearly equal in population as possible” and that they should only split counties, cities and other municipal lines if needed to equalize population.

“It’s sort of hard to draw map lines when you don’t know what the opinion is,” Senate Majority Leader Jake Corman, R-Centre, told reporters. “I mean, we can guess, but what if we guess wrong?”

House Republican spokesman Steve Miskin said much of the talk in recent days has been about “hypotheticals.”

“Without an opinion from the court about what their guidance is, it is only hypotheticals,” Miskin said. “Drawing a perfect map is in the eye of the beholder.”

Republican leaders also are hoping the U.S. Supreme Court will grant their request to keep the existing maps in use for this year’s races. On Monday, Justice Samuel Alito gave the other side until Friday to respond to the request.

Democratic Gov. Tom Wolf said he was embarking on a listening tour in the coming three days, seeking input from voters and people with strong feelings about redistricting. Wolf said in an interview in his Capitol offices that he sees himself as “the arbiter” and is determined to achieve what he considers a fair map.

“This is about the rules of the game,” Wolf said. “And if the game is not a fair one, it makes it suspect in the minds of the players.”

The court’s Democratic majority gave lawmakers and Wolf until Feb. 15 to submit an acceptable map, or the justices will develop one. They said they have hired an expert and imposed technical demands on those who plan to submit proposed maps to the court.

“Right now I’m optimistically figuring they’re going to come to me with a fair map,” said Wolf, who said late last week he also has hired a redistricting expert .

Pennsylvania’s status as a closely divided state is evident in that Democrats hold all four statewide offices, but Republicans have firm majorities in both legislative chambers. The Supreme Court has a Democratic majority, 5-2, but the congressional delegation is 13-5 in favor of Republicans. Of the eight most recently elected governors, going back to 1967, four were Republicans and four Democrats.