Indiana state Treasurer Richard Mourdock will officially announce his primary challenge to Sen. Dick Lugar (R-Ind.) on Tuesday, rolling out the backing of a majority of party officials from across the state. 

The endorsements will project an early show of strength for Mourdock, demonstrating that despite Lugar's campaign war chest, the longtime senator is in for a tough primary fight.     

Mourdock's first line of attack is an obvious one: that Lugar is far too cozy with President Obama. Along with Tuesday's announcement, the campaign is rolling out a web video highlighting the relationship between Obama and the longtime Indiana senator. 

The video starts with Obama's mention of Lugar in the speech announcing his '08 presidential campaign and a shot of the campaign ad Obama ran in Indiana that pictured him with Lugar.   

"He said that Lugar was among a handful of people ... 'who have shaped my ideas and who will be surrounding me in the White House,' " says the video in white text against a black backdrop.

The video references Lugar's support of the DREAM Act, the START treaty and his votes to confirm Obama's two Supreme Court nominees, all of which will be leading lines of attack against Lugar in the primary. 

The video employs a series of photos of Lugar alongside Obama and Sen. John KerryJohn Forbes KerryDemocrats debate how to defeat Trump: fight or heal GOP senators press State Department for Hunter Biden, Burisma records Krystal Ball hits media over questions on Sanders's electability MORE (D-Mass.) as the Republican worked with the administration during the lame-duck session to get the START Treaty ratified.