"He was probably more focused on the attorney general's race, but his voting record over the years on the issues has been great," said Branch, a Baltimore Democrat. "He's very, very smart, and he's always focused on doing the right things."

Del. Sheila E. Hixson, the Montgomery County Democrat who chairs Ways and Means, said she noticed Cardin was frequently missing votes but didn't press him for a reason. She said she didn't think any bills were harmed by his absence.

Of his missed votes, records show Cardin alerted the committee more than 100 times that he would be absent, but eight times failed to do so.

"I knew he wasn't there a lot," Hixson said. "If we were going to have a tough vote on something, I would have called him to make sure he was there."

Likewise, House Speaker Michael E. Busch said he wasn't overly concerned about Cardin's missed votes, noting the need of a part-time legislator to balance work with family obligations.

"As a citizen legislator, each member must balance their responsibilities in the legislature, particularly in committee, with other responsibilities, both professional and personal," Busch said in a statement. "I believe the work product of the Ways and Means Committee was outstanding this legislative session and did not suffer because any one member was not in attendance."

But Sen. Lisa A. Gladden, a Baltimore Democrat who is supporting Frosh, said she believed Cardin's lack of attendance calls into question his suitability for higher office. She pointed to a stunt Cardin pulled in 2009 in which he persuaded on-duty city police marine and helicopter officers to help him propose to his girlfriend by pretending to raid a boat the couple was aboard in Baltimore's harbor.

City police investigated what they said appeared to be a misuse of police resources, and Cardin pledged to reimburse the city for "whatever costs they deem appropriate." He later paid $300.

Gladden introduced a bill this year that would have imposed a $15,000 fine on any state or local official who misuses law enforcement resources

"I thought it was wrong," Gladden said of Cardin's use of police resources. "In a place like Baltimore City, where we have a high crime rate, we need every officer and every penny and dime available to us."

Gladden withdrew her bill, citing the election, but said she planned to reintroduce it next year.

According to recent polls, Cardin — the nephew of U.S. Sen. Ben Cardin — leads in the race to succeed Attorney General Douglas F. Gansler. Cardin led a Baltimore Sun poll in February with 18 percent of Democrats supporting him. Frosh trailed with just 6 percent. About two-thirds of voters were undecided.

Lublin said he believed Frosh and Braveboy could seize on Cardin's voting record to gain momentum in the race.

"One thing that resonates a lot for Cardin is his last name," Lublin said. "His uncle is enormously respected in Maryland, particularly in Baltimore and particularly in the Jewish community. Can Frosh or Braveboy make his voting record well known? I don't think this is the last time people are going to be asking him the question as to what he was doing during that time."

The Democratic primary is June 24. The winner will face two little-known candidates: a Republican, Towson attorney Jeffrey N. Pritzker, and a Libertarian, parole commission hearing officer Leo Wayne Dymowski.

Baltimore Sun reporters Timothy B. Wheeler and Quinn Kelley contributed to this article.