Senate Majority Leader Mitch McConnell (R., Ky.) warned on Wednesday that Democratic candidates had a "50-50" chance of winning a majority in the Senate in the upcoming general elections.Republicans currently hold a 53-47 majority in the Senate, but several Republican candidates are facing strong Democratic challengers. Senator Susan Collins (R., Maine) is in a difficult reelection campaign against Maine House speaker Sara Gideon, and Thom Tillis of North Carolina is behind in polling against Democrat Cal Cunningham. Meanwhile Lindsey Graham of South Carolina, one of the most prominent Senate Republicans, is tied in some polls with well-funded challenger Jaime Harrison."It's a 50-50 proposition," McConnell said of Democrats' chances in comments reported by Fox News. "We have a lot of exposure. This is a huge Republican class….There are dogfights all over the country."The Cook Political Report currently lists seven Republican seats as "toss-up," while elections for two Republicans — Martha McSally of Arizona and Cory Gardener of Colorado — are listed as leaning Democrat. McConnell, himself up for reelection, currently holds a strong lead against opponent Amy McGrath."If you look at the Democratic Party today, you ought to be frightened," McConnell said of current liberal candidates. "We're fighting for our way of life."President Trump is also fighting for reelection, with most polls predicting a likely win for Joe Biden. RealClearPolitics polling averages gave Biden a seven-point lead as of Thursday, although some pollsters believe Trump may yet win the race.