Quinnipiac University polls released Thursday show positive signs for Democratic Senate candidates in Maine, South Carolina and Kentucky. The surveys were conducted from July 30 to Aug. 3. 

One Maine poll shows Democratic candidate Sara Gideon with a 4-point lead on Sen. Susan Collins. The poll shows Gideon with 47% support and Collins at 43%. A South Carolina survey shows Democratic challenger Jaime Harrison tied with Sen. Lindsey Graham. Both candidates have 44% support.

A survey of Kentucky’s Senate race shows incumbent Republican Mitch McConnell with a 5-point lead over Democratic challenger Amy McGrath, a sign that the race could be tightening. The Senate Majority Leader has 49% support, while McGrath has 44% support.

But a recent Morning Consult poll showed McConnell with a 17-point lead over McGrath, 53% to 36%. Many consider McConnell to be vulnerable since he has among the worst approval ratings of any senator. In November 2019, Kentucky elected a Democratic governor.

"Big political names. Huge political stakes. High anxiety for the GOP. Three GOP Senators who easily won their last reelection bids are looking over their shoulders less than three months from Election Day," Quinnipiac University Polling Analyst Tim Malloy said about the results of the surveys.

Democrats will need to retake three or four Senate seats to win a majority in the upper chamber, depending on which party wins the White House. Recent general election polls show presumptive Democratic nominee Joe Biden with a strong lead over incumbent Donald Trump. On Thursday, famed presidential prognosticator Allan Lichtman said he believes Biden will win the election.

Other promising Senate races for Democrats include Arizona, North Carolina, Iowa and Montana.