Originally Published: 05 MAY 21 08:13 ET

By Ryan Nobles, CNN

(CNN) -- The campaign arm for Senate Republicans is set to launch a multi-media ad campaign targeting incumbent Democratic freshman Sen. Mark Kelly over his stance on immigration, a sign that Arizona could be one of the most important battlegrounds in the 2022 midterm elections.

The National Republican Senatorial Committee is launching a five-figure digital ad campaign and has plans to post billboards across the state attacking Kelly's immigration-related votes -- a key issue with voters, given the state's location along the southern border.

Kelly, a former astronaut and the husband of former Arizona Rep. Gabby Giffords, ran a largely biographical campaign in 2020 when he beat Martha McSally to serve out the remainder of the late Sen. John McCain's term. Now, Kelly is forced to run on his record in the Senate.

While Arizona voted for both Kelly and Joe Biden in 2020, the state is still considered to be a conservative stronghold and is key to GOP hopes of flipping control of the Senate. The seat is expected to be one of the most competitive races in the country.

Kelly has attempted to get out in front on the issue of immigration. Shortly after Biden's first address to a joint session of Congress, Kelly was quick to criticize the President for not making it a greater focus of the speech.

"While I share President Biden's urgency in fixing our broken immigration system, what I didn't hear tonight was a plan to address the immediate crisis at the border, and I will continue holding this administration accountable to deliver the resources and staffing necessary for a humane, orderly process as we work to improve border security, support local economies, and fix our immigration system," Kelly said in a statement.

The NRSC argues that Kelly talks tough when it comes to the Biden immigration policy, but doesn't vote that way, and accuses Kelly of not speaking up when Biden canceled the federal emergency declaration on border security.

"Mark Kelly might be new to the Senate, but he is already an expert in speaking Washington Politician. Mark Kelly has worked hand-in-hand with Joe Biden, Kamala Harris, and Chuck Schumer to create this border crisis. Now back in Arizona, Mark Kelly is pretending to care about the crisis he helped create," said NRSC Chair Rick Scott of Florida in a statement to CNN.

Kelly's office declined to comment to CNN on the ad campaign.

The campaign uses a series of message votes on border issues that Republicans offered up as amendments during the Senate passage of the Covid relief package. Those amendments, often offered by both Republicans and Democrats during the reconciliation process, are designed to force senators to make tough votes and rarely have anything to do with substantive policy issues.

Kelly has gone to lengths to offer support to Arizona GOP Gov. Doug Ducey in his efforts to deal with the situation at the border. Kelly and Democratic Sen. Kyrsten Sinema asked Biden to re-imburse the state after Ducey sent 250 National Guard troops to the region -- a move Kelly supported.

Ducey, who is term limited in his role as governor, has ruled out a challenge to Kelly.

Kelly has also visited the border on two different occasions, and he and Sinema pushed for $110 million in funding in the American Rescue Plan to help reimburse localities and organizations that are assisting there.

Scott sought to paint Kelly as said if the senator "a typical Washington politician," saying if the senator "truly cared about keeping Arizonans safe, he would have voted in favor of common-sense legislation to secure the border and enforce immigration laws."