(CNN) Unlike other Republicans in competitive races, Sen. Thom Tillis of North Carolina is running on his opposition to the impeachment of President Donald Trump.

In January, GOP Sen. Cory Gardner of Colorado launched ads on Facebook urging donors to give to him to protect the Republican majority. Republican Sen. Susan Collins of Maine aired personal testimonials on how she protects the state's small businesses. But Tillis' ads sent his supporters to a website -- senditorendit.com -- to register their opposition to removing the President from office.

On Wednesday, the Tillis campaign will blast out another four-figure digital ad on the topic, a clear sign that it views the issue as a political winner. In the ad, Tillis says that North Carolina is "sick" and "tired" of impeachment and "looking forward" to Washington addressing trade, economic and agricultural issues.

"The voters are going to have an opportunity to vote on the President in November," says Tillis. "I think they should set their sights on that and we should get back to work."

The ad features two Democrats running for the seat: state Sen. Erica Smith, who has said that she'd vote to impeach and remove Trump, and Cal Cunningham, the Democratic Senatorial Campaign Committee-endorsed candidate who supported opening an impeachment inquiry.

In December, the Democratic-controlled House passed two articles of impeachment -- abuse of power and obstruction of Congress -- against the President for pressuring Ukraine to investigate his potential 2020 political rival, former Vice President Joe Biden, while withholding military aid as leverage.

Sen. Thom Tillis, center, and other Republican senators hold a news conference in July 2017.

During the Senate trial, Democrats called for Tillis and other Senate Republicans to vote for new witnesses. Some with firsthand knowledge of the events, such as former national security adviser John Bolton , had declined to come before the House but would've testified before the Senate. In the end, Senate Republicans blocked new witnesses after only two Republicans -- Collins and Sen. Mitt Romney of Utah -- joined with the Democrats in favor.

"Thom Tillis has failed to be the independent voice North Carolinians expect from their Senator on issue after issue, including blocking witnesses in this sham trial, and is taking his cues from the White House and Washington party leaders instead of the people he's supposed to represent at home," said Cunningham in a statement.

Many Democrats view health care, not impeachment, as their primary message. On Tuesday, they took dozens of patients and doctors as guests to the State of the Union. Last week, House Democrats' campaign arm announced a million-dollar ad buy focused on lowering the costs of prescription drugs.

Tillis, however, has wielded impeachment against Democrats in North Carolina, which unlike Colorado and Maine backed Trump in 2016. The ad on Wednesday follows another his campaign aired in October not long after Pelosi announced the investigation.

"For the last several months our campaign has been pointing out that North Carolinians are sick of impeachment and want Congress to get back to work on addressing their needs," said Tillis campaign spokesman Andrew Romeo. "Senator Tillis is focused on producing results for the people of North Carolina, while his opponents are prioritizing partisan games to appease their radical, liberal base."

The Tillis campaign claims that its online fundraising has increased by more than 494% since September 24, when Pelosi announced the inquiry, and added tens of thousands of names to its email list with its impeachment-related efforts. The digital ad buys are a small portion of its campaign cash; at the end of 2019, Tillis had more than $5.3 million on hand.