WASHINGTON — Maryland’s redrawn congressional map, which paved the way for a Democratic victory in November, significantly al-tered the makeup of two of the state’s eight congressional districts, as expected, according to recently released demographic estimates.

The 6th Congressional District, which was reshaped to include a swath of heavily Democratic Montgomery County, is now 69 percent white, down from 87 percent in 2010, according to census data.

The shift stems from 7 percentage-point increases in each of the populations of African-American, Hispanic and Asian-American residents.

The 8th District, represented by Rep. Chris Van Hollen, D-Kensington, experienced a countervailing shift. The district’s share of white residents increased 14 percentage points, up from 56 percent to 73 percent, and its share of African-American, Hispanic and Asian-American residents fell by approximately 5 percentage points each.

The redrawn map helped Potomac Democrat John Delaney, a political neophyte, trounce 10-term Republican Congressman Roscoe Bart-lett, 59 percent to 38 percent.

“Martin O’Malley and the Democrats want to make sure there is nobody to stand in their way,” said David Ferguson, executive director of the Maryland Republican Party. “They have to divide and conquer in the areas where Republicans are stronger.”

The safeness of Van Hollen’s district — he has been re-elected with at least 60 percent of the vote every time since his first election in 2002 — allowed state lawmakers to shift some reliable Democratic votes into the 6th District, giving the party a better chance to pick up the seat.

It worked. Montgomery County residents voting in the 6th District broke heavily for Delaney on Election Day, 69 percent to 29 percent. And Montgomery was the best represented of the five counties encompassed by the district, contributing just under 50 percent of the vote.

Frederick County residents newly pulled into the 8th District went strongly for Van Hollen’s Republican opponent, Ken Timmerman, but were vastly outnumbered by Montgomery County Democrats.

Gerrymandering, redrawing electoral district lines for partisan advantage, is a “national problem” that “needs to be solved at the national level,” said Michael Cain, a political science professor at St. Mary’s College of Maryland.

But, he’s not optimistic it will be. “I don’t expect one party to unilaterally decide to give up their advantage in the state,” Cain said.

New database programs and computing abilities have compounded the problem by allowing state parties to redistrict in a more sophisticated and effective way, he said.

The state’s congressional map was redrawn by Gov. Martin O’Malley’s Redistricting Advisory Committee, based on demographic information collected as part of the 2010 decennial census. The plan was approved by the General Assembly in October 2011.

Maryland’s redrawn congressional districts were found to have the lowest average compactness of any state by two measures used by Azavea, a geospatial analysis software development firm that studied redistricting nationally.

State Republicans were outraged by the map and drummed up enough signatures to put it to a vote. But Marylanders approved the redrawn map at the polls, with 64 percent in favor of ballot question five.

“People don’t pay attention to redistricting,” said Delegate Michael Hough, R-Frederick, who contributed to the referendum. “A lot of people are just unaware of the map.”

Hough was also involved with a lawsuit, brought by a Prince George’s County-based political action committee, against the redrawn legislative map.

The Court of Appeals dismissed the suit in early November 2012, writing in an order that the redistricting “plan is consistent with the requirements of the Constitution of the United States and the Constitution of Maryland.”

“We thought it was going to be a bit of an uphill battle,” Hough said. “When the state does a gerrymandered map, the state can use its resources to defend itself.”

The lawsuit was financed by the Iowa-based Legacy Foundation, which aims to “advance individual liberty, free enterprise and limited, accountable government,” according to a mission statement on its website.

The plaintiffs will have 90 days to appeal once they receive the judge’s written opinion, and Hough said he “definitely” thinks they should.

The Legacy Foundation could not be reached for comment.

Facing a redrawn congressional map, the Maryland GOP plans to pound the pavement to meet constituents new and old, Ferguson said.

“We’re going to have to work harder to earn the trust of the voters who’ve never heard our candidates’ names,” he said. “We’re going to go after 100 percent of the voters out there.”

Cain said state Republicans would have a much better chance of picking up seats if they moved more toward the ideological center.

But, he cautioned: “The Republican Party has not come to me recently for advice.”