Republicans are hoping higher-than-expected voter turnout and a late surge in support will help win re-election for many incumbents in the Senate and House.
While Democrats were expressing hope they may make significant gains, late polls and early exit polling suggest a slip in support for Democratic challengers in a number of races.
Gary Bauer, president of American Values, predicted the expected Democratic sea change may be averted.
"I don’t see the kind of results in these early results -- the tidal wave for Democrats -- that a lot of big media was suggesting could happen," Bauer said. "NBC, just a few days ago, was suggesting that 53 to 60 Republican House seats could be up for grabs. I just don't see something like that developing."
Bauer said he thinks values voters -- the one group in America "who people seemed to want to not show up today" -- showed up.
"The marriage amendment has passed handily in Virginia," Bauer said. "I'm optimistic that we will see similar results in other states."
Still, Dems are expected to pick up a significant number of seats in both houses of Congress.
"We are feeling very, very good about things," said Sen. Charles Schumer, D-N.Y., chairman of the Democratic Senatorial Campaign Committee.
In Pennsylvania, Democrat Bob Casey Jr., son of former Gov. Bob Casey, is projected to defeat Sen. Rick Santorum, R-Pa., the incumbent, who has been a stalwart on pro-family issues.
In Vermont, independent Bernie Sanders -- the one-time Socialist Mayor of Burlington -- appears to have won the seat now held by another independent, former Republican Sen. James Jeffords, who is retiring.
In Indiana, Republican Sen. Dick Lugar, chairman of the Senate Foreign Relations Committee, has apparently coasted to a sixth term.
In West Virginia, the longest serving member of the Senate, Democrat Robert Byrd, has won re-election.
In Florida, incumbent Democrat Bill Nelson is a projected winner over Republican challenger Katherine Harris.
