When Robert C. “Bobby” Scott was elected to Congress in 1992, he was Virginia’s only black representative, chosen by voters in a serpentine district designed to include most of the state’s heavily African American neighborhoods.

Nearly 20 years later, in a rapidly diversifying state, Scott remains Virginia’s only non-white congressman. He still represents a district that stretches from Hampton Roads into Richmond with squiggly boundaries, drawn to maximize black votes.

Is that a problem?

That will be the central question facing the General Assembly when it returns to Richmond on Thursday to consider competing plans to redraw the borders of Virginia’s congressional districts in response to population shifts tracked by the 2010 census.

One proposal would cement the state’s status quo and strengthen incumbents. The other would siphon black voters out of Scott’s district and distribute them into a neighboring district, a proposal the legislative black caucus in the state Senate believes would boost minority representation.

“The African American voting populace is certainly not being given the opportunity to vote for candidates of their choice” under the current plan, said Sen. Mamie D. Locke (D-Hampton), who chairs the caucus.

According to census data, non-Hispanic whites make up only 65 percent of Virginia’s population. The state is more than 19 percent black and nearly 14 percent Hispanic and Asian.

Democrats who hold power in the state Senate have proposed a new map that would tighten Scott’s district closer to Hampton, Newport News and Norfolk, removing its Richmond territory. As a result, the percentage of black voters in his district would drop to about 42 percent. But that would allow a new 4th District to be drawn in Richmond and counties to its south, a seat where just over half of voters would be black.

That way, instead of controlling the destiny of one of 11 congressional seats, proposal supporters say, black voters would essentially have their say in two districts.

Scott, who said he could win reelection in a district with fewer black voters, backs the plan. “If you make the case, you should make a case for two districts,” he said. “Why should you make a case for just one?”

The Republican-held House of Delegates has advanced a plan that would change Virginia’s map less radically: The percentage of black voters in Scott’s district would rise from nearly 53 percent to 57 percent.

Del. William R. Janis (R-Goochland), the proposal’s architect, said he thinks the 1965 Voting Rights Act does not allow the state to drop the percentage of black voters in Scott’s district. The law requires that states not “retrogress” in terms of black representation, and it has been interpreted to promote majority-minority districts.

The Justice Department, which must review Virginia’s plan because of its history of racial discrimination, could reject the plan advanced by black Democrats in the state, he argued, because only one district would have a bare black majority.

“To me, it’s weighing a certainty against an uncertainty,” Janis said.

Virginia is hardly the only state where the racial makeup of the congressional delegation doesn’t match that of the state’s population. Neither Arkansas nor Tennessee has any black members of Congress, despite significant minority populations in both. Only one of Alabama’s seven congressmen is black, although more than a fourth of the state’s population is African American.

In the 1970s and 1980s, civil rights leaders pushed to increase the number of African Americans in Congress, said David Bositis, senior research associate at the Joint Center for Political and Economic Studies and an expert in black representation.

Because voting was so racially polarized, particularly in the south, that meant creating districts with high percentages of black voters, he said.

But Bositis said many civil rights leaders came to believe that tactic actually lessened black voting strength by cramming black voters into just a few districts. That became particularly apparent, Bositis said, after Republicans took control of the House of Representatives in 1994.

“After that, there was much more sensitivity to the partisan consequences of creating majority-minority districts, particularly majority-minority districts that were packed,” Bositis said.

Now, Bositis said, civil rights leaders tend to focus less on whether districts would result in the election of black candidates and more on whether the boundaries expand the power of black voters to choose candidates of their choice, of either race.

It’s a strategy bolstered by the willingness of white voters to support black candidates and vice versa — and it tends to favor Democrats.

Indeed, if the Senate plan were adopted in Virginia, it could make reelection difficult for Republican Rep. J. Randy Forbes, whose 4th District seat would be dramatically altered to include far more black voters who would probably support a Democrat.

That outcome would not likely please the GOP in a state where Republicans now hold eight of 11 congressional seats, a strong majority in the House of Delegates and the governor’s mansion.

“I think we will pass something close to our map,’’ Janis said.

Forbes has declined to comment publicly on the maps.

The House plan has received support from some black delegates, who say they like the Senate proposal in concept but have concerns about dramatically lowering the percentage of black voters in Scott’s district.

Former governor L. Douglas Wilder, the nation’s first elected black governor, said he shared those concerns. The issue isn’t whether Scott could win a district where only 40 percent of voters are black but if other black candidates could do so in the future, he said.

“It’s not for him,’’ Wilder said.

Legislative leaders said they expect to be in Richmond only briefly, long enough this week to formally adopt competing maps and appoint a committee to negotiate their differences.

Then it will be a question of which side blinks first.

Since Democratic incumbents have signed off on the House plan — even Scott said he could live with the status quo if adopted by the legislature — it could win out.

“We think it’s the right thing to do, and it’s a good plan,’’ said Sen. Mary Margaret Whipple (D-Arlington), chairwoman of the Senate Democratic caucus. “It doesn’t mean we don’t have a certain dose of reality about it.”