At the time of his 2017 nomination for the U.S. Court of Appeals for the Eighth Circuit, the American Bar Association's Standing Committee on the Federal Judiciary unanimously voted to give Grasz a "not qualified" rating for the position.

While in private practice, Grasz challenged a state constitutional provision restricting ownership of agricultural land under the Commerce Clause.

[1] Grasz has also written numerous op-eds, including one in 2012 criticizing John Roberts as "the one who ushered in the ultimate transfer of limitless power to the federal government" for his decision in National Federation of Independent Business v. Sebelius, which he described as "unsupportable in terms of its legal reasoning and adherence to longstanding rules of constitutional interpretation or construction".

In a statement, the chair of the ABA's standing committee that reviews nominees said that Grasz's "temperament issues, particularly bias and lack of open-mindedness, were problematic".

[18] Nebraskan Senators Ben Sasse and Deb Fischer defended Grasz's reputation and accused the ABA of conducting a biased evaluation "based on limited facts".

[2] On November 15, 2017, Pamela Bresnahan, the chair of the ABA's Standing Committee on the Federal Judiciary, testified before the U.S. Senate in order to explain the organization's vetting of Grasz.

[21] On November 30, 2017, Senate Judiciary Committee Chairman Chuck Grassley stated that follow-up materials from Grasz "appear to indicate that the ABA relied on faulty information in their evaluation".

[28] On November 15, 2021, Grasz, writing for a unanimous panel, denied qualified immunity to a police officer who shot service dogs.

[29] [30] On December 15, 2022, Grasz, writing for a unanimous panel, reversed the finding of a jury in a lower court that a man who secretly video recorded his underage niece was guilty of two counts of production of child pornography.