WASHINGTON, Nov. 3 (UPI) -- Democratic Sen. Barack Obama may win the U.S. presidency narrowly Tuesday, or he may win by a big margin. But either way -- and even if Republican contender Sen. John McCain pulls off an upset -- the outlook for Republicans in Congress is dire.

The Democrats are poised to make sweeping gains in both the Senate and the House of Representatives. They could get a filibuster-proof majority in the Senate, allowing them to launch a blizzard of reform legislation comparable only to the periods 1933-36 and 1965-66 in U.S. history.

The Democrats are challenging hard all across the nation, showing excellent prospects for carrying states in the presidential race and picking up House and Senate seats in states that have been Republican strongholds for a generation or longer.

Key bellwether states where the Dems are charging hard stretch all the way across the U.S. heartland that as recently as four years ago was a monolithic stronghold for President George W. Bush and the Republican majorities he still then enjoyed in both the House and the Senate.

Obama looks almost certain to make massive gains in the West and Southwest, long the strongest bastion of national conservative Republican free-market political forces. Polls indicate Obama has decisively won the battle for the Latino vote and, along with the defection of key white working-class voters, he appears poised to carry -- and chalk up House gains in -- New Mexico, Nevada and Colorado. Even McCain's home state of Arizona, which already has an able and popular Democratic governor in Janet Napolitano, could see Dem gains.

The Democrats look certain to surge from 50 seats in the Senate to at least 57, and quite possibly 59. Their hopes of getting the magic 60 figure, which would give them a filibuster-proof power to approve any government or Supreme Court nominations they want, hinge on, of all things, a comedian -- Al Franken, who is posing an unexpectedly strong challenge to veteran incumbent Republican Sen. Norm Coleman in Minnesota.

If Franken can pull off a dark horse victory there, as Sen. Jim Webb, D-Va., did two years ago, expect Democratic sweeps all across the board. We think he can.

Former Gov. Mark Warner also looks poised to carry Virginia for the Democrats in the Senate, giving them a lock on both Senate seats in the Old Dominion.