Even if the Court of Appeals makes only a few changes to the map, Republicans say they'll make redistricting a major campaign issue.
"This is just a nice reminder that even monopolies sometimes have to answer to a higher authority," said Ehrlich, a Baltimore County congressman.
But Maryland Democrats dismiss talk that the court's decision represents a big victory for the GOP.
"That's what you say when you don't have any issues," said David Paulson, a spokesman for the state Democratic Party. "Using the court decision as a springboard for that kind of message says to the voters, 'Hey, vote for us just because we're the other guys.' Let's instead talk about issues that actually matter to people."
Political observers suggest that legislative redistricting might be too obscure a subject to arouse much interest among most voters - unless the court makes major changes.
The Court of Appeals rejected the plan drawn up by Glendening and Democratic legislative leaders to reshape the districts of all 188 General Assembly members. The judges found that "significant portions" of the new map violate requirements of the Maryland Constitution and said it would create its own plan - one that could subsequently be challenged in federal court.
The Court of Appeals is expected to act quickly. But its brief order did not set a deadline for when it would complete its work, nor did it indicate how extensive the changes might be.
No matter how radically the court alters the districts, no one seriously believes that the GOP can capture control of the Senate or House of Delegates this year. But Republicans hope they can make up for losses suffered in the 1998 election - and perhaps even gain a few seats, particularly if the court redraws several of the more contested districts.
"This is going to help the Republicans, because it does not cast the Democrats in a favorable light," said Matthew Crenson, a political science professor at the Johns Hopkins University. "I doubt they would take control over the Assembly."
More significantly, Ehrlich and his supporters believe that the redistricting issue can help them illustrate what they mean when they criticize the one-party control of Maryland government.
"It's been hard for people to pin down in their minds what it meant," said Carol L. Hirschburg, a Republican consultant. "So many of the arguments had been insider-type arguments. With the brazen redistricting plan that was passed this year, people were able to see, and felt affected by it. Now, you have the court saying it, too."
Republicans also have been emphasizing the efforts by prominent Democrats, including Senate President Thomas V. Mike Miller, to call or meet with members of the court. The court revealed those contacts in a pair of unprecedented public statements.
While the judges cut off the contacts as soon as they realized that the lawmakers wanted to discuss pending redistricting lawsuits, Republicans leaders have criticized the lawmakers' actions and filed a series of legal and ethics complaints.
"As far as the arrogance of power, the effort from the Senate president and other members of the General Assembly to contact and try to influence the judicial branch of government is a better example of this perception that they can do what they want, how they want, when they want," said Del. Alfred W. Redmer Jr., a Baltimore County Republican and the House minority leader.
Even some prominent Democratic lawmakers say that the efforts by Miller and others may have helped persuade the court to throw out Glendening's redistricting plan.
"I had a sick feeling that this was coming, in light of the public acknowledgement of these interventions led by senators," said Del. Howard P. Rawlings, a Baltimore Democrat. "They needed to send a message that it had integrity."
Republicans hope to carry that message from the court through the November election - particularly as they try to capture moderate voters in a state where registered Democrats outnumber Republicans almost 2-to-1.
"There is definitely a vote in the state which wants to see some type of balance of the power," said GOP political consultant Kevin Igoe. "There are voters who truly believe in the checks-and-balances system, and they want both parties at a certain level of strength to keep an eye on each other."
Sun staff writer Ivan Penn contributed to this article.