House Judiciary Committee Democrats plan to press Attorney General Bill Barr at a hearing today on what they'll argue is his politicization of the Justice Department to serve President's Trump's personal agenda.

Why it matters: Democrats have a lot of pent up frustration over a series of recent policies put forth by the DOJ, and have been preparing months for this moment.

The big picture: This is the first time Barr will appear before any House Judiciary Committee — both during his tenure under the Trump administration and as attorney general under George H.W. Bush, according to the committee's Democratic counsel.

What to expect from Democratic members, per their committee counsel:

• They'll claim that under "Operation Legend," a Trump administration initiative in which federal agents were dispatched to U.S. cities to fight violent crime, Barr has "flooded the streets of American cities with federal agents against the wishes of state and local authorities, and under pretty flimsy legal pretext."
• They'll argue the operation is solely a political stunt for Trump's reelection campaign.
• Members will also grill Barr on what they'll assert is his use of the department to "spread disinformation about voter fraud, its failure to enforce the Voting Rights Law, and his attempt to change the census rules" to help Trump's reelection chances.
• They'll argue Barr is "overreaching" into certain cases, such as that of Michael Cohen, in order "to go after the president’s enemies and protect him from accountability.”

The counsel noted that members will bring up several different subjects — including the firing of inspectors general from several government agencies; the forced removal of George Floyd protesters from Lafayette Square last month; and lingering questions about his handling of the Mueller report and Trump's subsequent impeachment trial.

• But each round of questioning will lead to one central theme: "That the attorney general uses the Justice Department to serve the president’s petty political interests," the counsel said.

The other side: A senior GOP aide tells Axios that Republicans on the committee plan to focus on:

• What they will claim is Barr’s "outstanding efforts to restore law and order in liberal cities that are under attack from violent left-wing mobs."
• Barr "cleaning up the mess made by the Obama/Biden Justice Department," specifically in relation to FBI surveillance of Trump's 2016 campaign.
• Defending Barr from the Democrats’ "endless fishing expeditions" against the president and his administration.

What's next: The hearing will begin at 10 a.m. on Capitol Hill.

Go deeper:Read Barr's opening statement attacking Dems and "bogus" Russia probe