GOP contenders gain ground over Dems in crucial Senate races, according to poll.

In recent polls, Republican Senate candidates are narrowing the gap between themselves and their Democratic opponents in key races, potentially determining which party will control the Senate and by what margin.

In Pennsylvania, a new CNN poll by SSRS shows that Republican Senate candidate Dave McCormick and longtime Senator Bob Casey Jr., D-Penn., are tied in the top battleground state.

In the survey, McCormick's campaign was neck and neck with Casey's advantages of being an incumbent and having a well-known family with deep roots in Pennsylvania, both at 46%.

Analysts have observed that McCormick faces a name identification challenge, as previous polling has shown him trailing Casey to varying degrees.

With less than 10 weeks until the general election, voters, particularly those in Pennsylvania, are paying attention, and those who lean Republican are supporting McCormick's campaign.

In Arizona, former gubernatorial candidate Kari Lake came close to Rep. Ruben Gallego, D-Ariz., in a new poll, with Lake finishing just three percentage points behind him, 47% to 44%.

In Wisconsin, Sen. Tammy Baldwin, D-Wis., narrowed Eric Hovde's lead to single digits, winning 51% to 45%, while in Michigan, Rep. Elissa Slotkin, D-Mich., also reduced former Rep. Mike Rogers' lead to single digits, with a score of 47% to 41%.

In Nevada, Sen. Jacky Rosen, D-Nev., leads Ret. Army Capt. Sam Brown by 10 points, with Rosen receiving 50% of the vote as she fights to retain her seat in the swing state.

As the election nears, GOP strategists predict that average voters will start paying attention and supporting GOP candidates.

According to the Cook Political Report, the Senate contests in Pennsylvania, Arizona, Wisconsin, and Nevada are still considered "Lean Democratic."

With the best chance of going Republican, Michigan's race was rated as a "Toss Up" by the handicapper.

The Senate race in Pennsylvania is crucial because strategists predict that incumbent Casey's performance will be closely tied to Vice President Kamala Harris's, with the strongest intensity, meaning her performance will significantly impact his success or failure.

In the recent CNN poll, both former President Donald Trump and Harris received 47% each.

A poll surveyed 4,398 registered voters in six states and queried them both online and by telephone between August 23 and August 29. The margins of error were +/- 4.7% in Pennsylvania and Arizona, +/- 4.9% in Michigan and Nevada, and +/- 4.4% in Wisconsin.