Shanlon Wu is a former federal prosecutor and CNN legal analyst. He served as counsel to Attorney General Janet Reno. Follow him @shanlonwu. The views expressed in this commentary are his own. View more opinion articles on CNN.

(CNN) What can we expect July 24 when Robert Mueller, the former special counsel, testifies in back-to-back hearings before the House Judiciary and House Intelligence Committees?

We can expect the testimony that Attorney General William Barr should have given. In short, Mueller will act and testify with all the dignity and integrity lacking in the current attorney general. Mueller will be factual, dispassionate and, most of all, accurate in his testimony.

Shanlon Wu

There will be no partisan spin. While we will not hear Mueller express sympathy for President Donald Trump's feelings (or anyone else's feelings), neither will we hear him express moral outrage over Trump's actions. Mueller will also defend to the death his right not to speculate by reciting -- mantra-like -- his belief that his testimony must be limited to the four corners of his 400-page report.

Therefore, Democratic members of Congress who view Mueller's testimony as an opportunity to conclusively show Trump's guilt will be disappointed as much as those Republican members who think Mueller's testimony will fully exonerate Trump. In truth, his testimony represents a historically unique opportunity to demonstrate for the American people how a republic can properly function as well as show those who support the move how to muster the necessary political will to commence an impeachment inquiry.

To accomplish this, the Democratic members must understand the difference between questions asked in direct examination and questions asked in cross-examination. The former will work wonders with Mueller while the latter are doomed to failure.

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