WASHINGTON — Former U.S. special counsel Jack Smith is testifying before the Senate Judiciary Committee in a closely watched hearing focused on the investigative methods used during his criminal probes of President Donald Trump and people connected to efforts to challenge the 2020 election results.

The Republican-led committee has framed the hearing around allegations that Smith abused his authority and improperly targeted Republicans. Judiciary Committee Chairman Chuck Grassley has argued that the investigation swept in Republican lawmakers and conservative figures in ways that deserve greater scrutiny. Democrats dispute that characterization and say Smith was carrying out a criminal investigation based on evidence rather than political affiliation.

Smith, who was appointed special counsel by then-Attorney General Merrick Garland in November 2022, led two federal prosecutions of Trump: one involving efforts to overturn the 2020 presidential election and another involving classified documents retained after Trump left office. Both cases were later dropped after Trump returned to the presidency, consistent with longstanding Justice Department policy against prosecuting a sitting president.

A major focus of the Senate hearing is Smith’s office seeking telephone records connected to Republican members of Congress. These records, often called toll records or call-detail records, can show when calls were made, the numbers involved and their duration, but generally do not include the content of conversations.

Republican lawmakers have sharply criticized those investigative steps, arguing that obtaining records associated with members of Congress raised concerns about privacy, legislative privilege and potential political misuse of federal law-enforcement powers. Grassley has also released several batches of documents from Smith’s investigation and has accused the former special counsel of conducting an improper probe.

Smith has confirmed that his office sought records from telecommunications companies as part of the investigation. His position has been that such requests were lawful investigative tools and that lawmakers were not targeted because of their political views.

Another issue expected to receive significant attention concerns text messages involving members of Congress that appeared in material obtained from White House staffers’ government devices. Republicans have questioned why Smith did not previously disclose more clearly that investigators had encountered congressional communications while reviewing those records.

Smith’s defense is expected to emphasize a distinction between directly subpoenaing the content of lawmakers’ messages and encountering their communications in material lawfully obtained from other individuals or government devices.

The hearing also reflects a much broader political and legal dispute over the limits of federal investigative power. Republicans argue that the Trump-related investigations became overly aggressive and politically tainted. Democrats counter that investigators were examining an extraordinary effort to overturn the result of a presidential election and that the legality of investigative steps should be judged by established criminal-procedure standards rather than the political identity of those involved.

Smith is also expected to reject allegations that his work was politically motivated and to defend his decisions as based on facts, evidence and federal law.

The Senate hearing therefore goes beyond Smith personally. It raises larger questions about how federal investigators should handle evidence involving elected officials, what protections members of Congress should have when their communications become relevant to criminal investigations, and how investigators can maintain public confidence when politically sensitive cases involve senior government figures.

Tuesday’s testimony is expected to remain one of the most contentious congressional examinations of the Trump-era investigations, with Republicans focusing on alleged investigative overreach and Democrats defending the legitimacy of the underlying federal probes.