Senate Majority PAC, the top super PAC for Senate Democrats, reserved $5 million for television and digital advertisements in the Kansas Senate race through Election Day.

The commitment targets the contest between Republican incumbent Sen. Roger Marshall and Democratic nominee Adam Hamilton, a pastor. Kansas has long been considered a solidly Republican state, but recent polling has shown the race tightening into a tossup ahead of the Nov. 3 midterm elections.

The Democratic investment follows Republican outside groups' decision last week to spend more than $10 million in the race. Public and private polls have indicated Hamilton tied or even leading Marshall in some surveys.

Additional Democratic spending has also targeted the state in recent weeks, including nearly $700,000 from a group affiliated with former Vice President Kamala Harris' super PAC and nearly $5 million from an outside group backed by a local attorney. Other reports noted further ad buys totaling several million dollars from various Democratic-aligned PACs.

The race has drawn attention due to economic pressures in the state, including high diesel and fertilizer prices. Republicans have expressed concern about the competitiveness in what was expected to be a safe seat.

Marshall won his Republican primary with minimal opposition, while Hamilton secured the Democratic nomination with about 35 percent of the vote in an August primary featuring multiple candidates.