WASHINGTON -- Rep. James R. Langevin, if reelected, might have a crack at the chairmanship of a House subcommittee that deals with threats to national security.

Rep. Patrick J. Kennedy would expect some share in the power to set legislative priorities in the next Congress, pushing his signature health-care issues onto the House ``to do'' list.

Democrats collectively would launch investigations into the war in Iraq, stifle the Republican campaign for tax cuts, and press for freer spending on an array of domestic programs.

For the next -- and last -- two years of President Bush's term, in other words, a Democratic-ruled House would have the clout to challenge this White House as it has never been challenged from Capitol Hill.

Although analysts caution that much could change in the month remaining before the congressional elections, many see better chances for a Democratic takeover in the storm of publicity surrounding a former GOP congressman's dealings with teenage House pages.

Norman Ornstein, a scholar of congressional affairs at the American Enterprise Institute, estimates a 70-percent likelihood that the GOP will lose its House majority.

There are 230 Republicans and 201 Democrats in the House today, with one independent who caucuses with the Democrats, as well as three vacancies, two in seats formerly held by Republicans and one opened by a Democrat.

By the numbers, therefore, a net partisan gain of 15 seats would give the Democrats a bare majority. That arithmetic has not changed appreciably in months; political observers have long considered it a distinct possibility that majority control of the House could change hands with this election.

A new bipartisan survey, the Battleground Poll, found some shifts in national mood that favor the Democrats in ways that could increase the number of seats considered competitive.

For example, the poll, conducted before the House e-mail scandal broke, found that black voters and other members of the Democratic party base were unusually intent on voting this year. That is ominous for the GOP, which in recent years has been able to depend on greater energy from its base, especially religious conservatives, to translate into an edge in turnout.

Democratic pollster Celinda Lake and Republican Brian Nienaber agreed -- as did a number of independent analysts -- that the House e-mail scandal could dampen enthusiasm among religious conservatives to turn out to support the GOP.

Langevin said in an interview last week that he has ``a tremendous hope'' that the Democrats will take over the House. If they do, said Langevin, a member of the Armed Services Committee, party leaders are certain to launch investigations of what has gone wrong with the American military enterprise in Iraq.

ufcontactjmulligan@belo-dc.com / (202) 661-8423