Republicans are either leading in Georgia, Kentucky and Louisiana or will likely win runoff elections, according to a NBC/Marist poll released Sunday.
In addition, the Republican nominee in Iowa, Joni Ernst, now has a 7-point lead over Democratic challenger Rep. Bruce Braley, according to a Des Moines Register poll released Saturday.
Most polls have shown until now that the four races have essentially been deadlocked in the closing weeks.
The GOP needs to win a net total of six Senate seats to take control of the chamber, with essentially only the West Virginia and Montana contests apparently in hand.
In Kentucky, Senate Majority Leader Mitch McConnell appears to be pulling away from Democratic challenger Alison Lund Grimes, reaching the critical 50 percent mark with Grimes now at 41 percent.
At a campaign stop Saturday night in Sterling, Ky., McConnell said that Grimes falsely accusing him of trying to privatize Social Security was proof that she was running a losing campaign.
A victory in the battleground state of Iowa is as critical for Democrats and it is for Republicans.
Senate Majority Leader Harry Reid on Friday hinted that an Ernst victory would essentially throttle Washington Democrats’ agenda.
“Mitch McConnell would be leader of the United States Senate, who agrees with her on everything,” Reid said on a conference call to the Progressive Change Campaign Committee, trying to rally the liberal group to help make a final push for Braley. “Think of what [that] would mean for our country.”
In Georgia, Republican nominee David Perdue is now ahead of Democrat Michelle Nunn, 48-to-44 percent, which suggests Perdue could get 50 percent of the vote on Tuesday and avoid a runoff.
In Louisiana, three-term incumbent Democratic Sen. Mary Landrieu has 44 percent of the vote in a three-way race with GOP Rep. Bill Cassidy, at 36 percent, and Republican Rob Maness, at 15 percent.
However, in the likely scenario that Landrieu gets less than 50 percent of the vote and advances with the second finisher, Cassidy, he would likely get most of Maness’ votes and ultimately win.