Senate Majority Leader Harry ReidHarry ReidThe Memo: Trump pulls off a stone-cold stunner The Memo: Ending DACA a risky move for Trump Manchin pressed from both sides in reelection fight MORE (D-Nev.) is hosting a fundraiser for Alison Lundergan Grimes, Senate Minority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellSenate passes 0B defense bill Overnight Health Care: New GOP ObamaCare repeal bill gains momentum Overnight Finance: CBO to release limited analysis of ObamaCare repeal bill | DOJ investigates Equifax stock sales | House weighs tougher rules for banks dealing with North Korea MORE's (R-Ky.) Democratic opponent.

The move marks a shift for Reid, who late last year said he wouldn't campaign against McConnell because he didn't think it was "appropriate." 

Though McConnell pledged not to campaign against Reid during his 2010 race, he also shifted course and helped Reid's GOP opponent, Sharron Angle, raise money.

In 2004, GOP Senate Leader Bill Frist (R-Tenn.) campaigned for John ThuneJohn Randolph ThuneAviation panel recommends Trump roll back safety rules Overnight Regulation: House moves to block methane rule | Senators wrestle with allowing driverless trucks | EPA delays toxic waste rule Overnight Tech: Senate looks at self-driving trucks | Facebook to keep ads off fake news | House panel calls Equifax CEO to testify MORE (R-S.D.) against then-Democratic Leader Tom Daschle (D-S.D.).

The fundraiser, first reported by Kentucky news outlet Channel 2, is scheduled for Oct. 11 at a McCormick & Schmick's restaurant in Las Vegas, and is organized by the Searchlight Leadership Fund, an organization Reid founded.

Tickets range from $1,000 for an individual to $5,000 for a political action committee co-host.

The Kentucky Republican Party pounced on the fundraiser. Spokeswoman Kelsey Cooper drew ties between the candidate and Reid's positions on coal.

"It should tell Kentuckians all they need to know that the biggest supporter of Alison Lundergan Grimes' campaign is Harry Reid, the man who thinks 'coal makes us sick.' If Alison was elected to the Senate, it would ensure that liberal Harry Reid and Barack ObamaBarack Hussein ObamaGOP rep: North Korea wants Iran-type nuclear deal Dems fear lasting damage from Clinton-Sanders fight Iran's president warns US will pay 'high cost' if Trump ditches nuclear deal MORE continue to set national coal policy rather than a Kentucky champion for coal, Mitch McConnell," Cooper said in a statement.

Coal mining is a big industry in Kentucky, and Republicans believe Lundergan Grimes may be vulnerable because of Democratic-backed policies to curb emissions from coal-fired power plants, which opponents say will hurt the coal industry.

The Lundergan Grimes campaign and Reid's office didn't respond to requests for comment.