A sizable majority of Americans think the District should have a full voting member in the House, but reaction is mixed to a bill pairing a new D.C. seat with an extra representative for Utah, according to a national Washington Post poll.

Overall, 61 percent of adults polled Sunday say the nation's capital should have a full House representative, with majorities agreeing across party lines.

But only 49 percent back the D.C. voting rights bill that cleared the House last week and that is headed for the Senate. That legislation would expand the House by two seats: one for the overwhelmingly Democratic District and one for the next state in line to pick up a representative -- heavily Republican Utah. The poll found 37 percent were opposed to the bill, and 14 percent had no opinion.

The biggest drop in support between the two questions came from Democrats. Although nearly seven in 10 Democrats want the District to have a full seat in the House, fewer than half -- 47 percent -- support the current bill, according to poll results.

"People support the principle" of a vote for the District, said Ilir Zherka, executive director of DC Vote, an advocacy group. "I think it's a little bit harder for some people to say, 'We should balance these votes out.' "

The bill's sponsors -- Rep. Thomas M. Davis III (R-Va.) and the District's non-voting delegate, Eleanor Holmes Norton (D) -- said a bipartisan deal is necessary to win passage in the Senate.

"We're just trying to look at the practical side," Davis said.

The poll was conducted by telephone among a random national sample of 788 adults. The margin of sampling error for the overall results is plus or minus 3.5 percentage points.

House Democrats have made approval of the D.C. vote bill a priority since taking control of the chamber this year, and nearly all party members voted for it when it passed 241 to 177 last week.

Republican House leaders opposed the measure, arguing that it violates the constitutional requirement that House representatives come from states. Some Republicans also worried that it could establish a precedent leading to the District eventually getting two senators.

The Senate minority leader, Mitch McConnell (R-Ky.), is also against the legislation.

"His disagreement with the bill is entirely constitutional in nature," said his spokesman, Don Stewart. "A poll won't change the unconstitutional nature of the bill, in his view."

The White House has threatened a veto if the bill passes the Senate.

Despite such opposition, a narrow majority of Republicans -- 52 percent -- back the legislation, along with independents -- 54 percent.

"This is not a party issue, except to the insiders," Davis said. He noted that the poll found clear majorities of Republicans, as well as Democrats, supporting the broad idea of giving the District a full House vote. "Most Americans feel this ought to happen," he said.

Legal scholars have differed over the bill's constitutionality. Supporters say the Constitution gives Congress such sweeping power over the District that lawmakers can give the city a House representative.

Norton suggested that some opposition to her bill might be because of a lack of awareness that the measure includes a representative from Utah. Democrats "know they're for the bill for D.C. There has been almost no attention paid to Utah," she said.

But the bill has drawn criticism from statehood advocates and some other proponents of more expansive D.C. voting rights. They contend that the legislation sells the city short by providing representation in the House but not the Senate. Norton argues that a gradual approach to full representation is most likely to succeed.

The legislation would guarantee Utah the extra House seat until 2012. Then it would go to whichever state would be due to pick up a representative, based on the 2010 Census.

Polling analyst Jennifer Agiesta contributed to this report.