Senate hearings begin Wednesday on whether to confirm U.S. Attorney Loretta Lynch as President Obama’s next attorney general, with Judiciary Committee members set to question her aggressively on such issues as immigration law and potential overreaches by the IRS and federal law enforcement.

The hearings in the GOP-led Senate Judiciary Committee are expected to begin with Republican members asking Lynch, the U.S. attorney for the Eastern District of New York, about whether she thinks Obama has overstepped his executive authority by deferring deportation for millions of illegal immigrants.

“It will be a long first day, because my approach … is to allow for as many questions as necessary to ensure that members have a chance to receive answers in person if they’d like,” said committee Chairman Sen. Chuck Grassley, R-Iowa. 

In excerpts of her prepared remarks released Wednesday morning, Lynch does not discuss immigration but vows that the Constitution "will be my lodestar as I exercise the power and responsibility of that position." 

In the excerpts, she says she looks forward to "fostering a new and improved relationship with this Committee, the United States Senate, and the entire United States Congress - a relationship based on mutual respect and Constitutional balance." 

Other first-up questions will likely be about whether the IRS broke the law when targeting Tea Party groups and other conservative organizations when they applied for tax-exempt status several years ago.

The Justice Department under outgoing Attorney General Eric Holder, whom Lynch would replace, is apparently still investigating the incidents. The agency did not return a call Tuesday seeking confirmation.

The 55-year-old Lynch -- a black, Harvard-educated lawyer -- is also expected to address the issue of states legalizing the sale and possession of marijuana. The Justice Department’s position is that this violates federal law, but the agency has so far taken a hands-off approach to prosecution.

Obama nominated Lynch in November 2014 when Democrats controlled the Senate through the end of the year. However, Republicans were able to hold off the confirmation process until they took charge of the Senate in January, as a result of the elections, arguing committee members from both sides needed more time to prepare.

Grassley has attempted to assure the public that Republicans didn’t stall the process until they took control of the upper chamber.

“She’ll receive a fair but thorough hearing,” he said earlier this month. “And I expect that she’ll be forthright in return.”

Though Lynch is expected to face tough questions, she is generally expected to be confirmed. She is widely respected in the legal community, and her personal and professional records appear scandal free.

The full Senate also must approve Lynch’s appointment. She will need 51 votes to win confirmation, and a final vote is not expected until at least late February.

Her biggest challenge could be explaining her support and participation in civil forfeitures, a legal process in which law enforcement agencies can seize money and other assets without charging or convicting the owners and that Holder recently scaled back, amid widespread criticism.

Lynch last January said her office collected more than $904 million in criminal and civil actions in fiscal 2013.

The policy generates money for law-enforcement efforts and lessens the burden on taxpayers, but critics say it is “an abuse of due process.”

Just days before Lynch’s confirmation hearings, Holder announced significant changes to the policy, including that federal agencies will no longer be able to accept or "adopt" assets seized by local and state law enforcement agencies -- unless the property includes firearms, ammunitions, explosives, child pornography or other materials concerning public safety.

Holder described the changes as the "first step in a comprehensive review."

Earlier, he said the Justice Department collected roughly $8.1 billion in civil and criminal actions in fiscal 2013 -- roughly three times the appropriated $2.76 billion budget for the 94 U.S. attorney’s offices and the main litigating divisions, in the same period.

Despite Holder’s changes, Capitol Hill Republicans on Tuesday reintroduced legislation to tighten restrictions.

"The federal government has made it far too easy for government agencies to take and profit from the property of those who have not been convicted of a crime,” said Sen. Rand Paul, R-Ky., whose FAIR, or Fifth Amendment Integrity Restoration Act, is also being reintroduced in the House by Rep.Tim Walberg, R-Mich.

Other concerns raised about Lynch include her decision to protect details of a federal case related to a stock-fraud scheme.

The defendant pleaded guilty in 1998, before Lynch started working at the Eastern District office.

But critics, including lawyers who fought to have more details of the case made public, say the defendant should have paid roughly $40 million in forfeitures and restitution, not the $25,000 fine he received.

And they suggested Lynch tried to block efforts to further expose the case, which could have helped plaintiffs recover some of their losses.

The defendant’s lawyers have said their client helped in a major national security probe.

If confirmed, Lynch, a North Carolina native, would become the first black woman to serve as U.S. attorney general, replacing Holder, the first black man to hold the position.

Last week, the Senate committee released a Justice Department review of Lynch in which she received mostly high ratings for her management skills.

But the review also identified areas for improvement, including the office’s responsiveness to public records requests made under the federal Freedom of Information Act.

Supporters of Lynch praised her Tuesday.

Former FBI Director Louis Freeh said Lynch works in the “most complicated criminal justice forum” in the country and that she has gotten “tremendous accolades and praise” from federal agents.

“That’s high praise,” he said. “She’s efficient and fair.”

New York City Police Commissioner William Bratton said he worked with Lynch on two occasions -- in 1994 and again in 1996. Bratton said he found Lynch “collegial, very approachable and well prepared.”

Lynch has since 2010 been the top prosecutor for a district that includes Brooklyn, Queens, Staten Island and Long Island, having also held that role from 1999 to 2001.

As a prosecutor, she was best known for her prosecution of the four New York police officers charged with violating the civil rights of Abner Louima, a Haitian immigrant who was beaten and sodomized while in custody.

A second confirmation hearing in the Judiciary Committee is scheduled for Thursday and will include testimony from former CBS investigative reporter Sharyl Attkisson, who filed a lawsuit against the Obama administration claiming it hacked into her computer. Lynch is not scheduled to testify.

Fox News' Lucas Tomlinson and The Associated Press contributed to this report.