FOUR OF THE FIVE Democrats running for governor declined yesterday to question state Attorney General Kathleen Kane's controversial decision to shut down a corruption investigation that reportedly captured four Philadelphia legislators and a judge accepting cash or gifts from a lobbyist.

"It's very hard to second-guess the statements that have been made about the prosecution, whether it could have gone forward or not," U.S. Rep. Allyson Schwartz said about the case.

The Inquirer first reported earlier this month that Kane ended the probe that started in late 2010, near the end of Gov. Corbett's time as the attorney general.

Kane calls the investigation "deeply flawed" and says federal prosecutors and the Dauphin County District Attorney's Office, which has jurisdiction in Harrisburg, reviewed it at her request and agreed that it could not be successfully prosecuted.

State Treasurer Rob McCord said it would be "boneheaded" to comment on the case without "real facts in front of me."

McCord then raised one of the most charged aspects of the controversy: Kane's claim that the lead agent in the investigation told senior staffers at the Attorney General's Office that he was instructed by his supervisor to focus "only on members of the General Assembly's Black Caucus."

McCord said there needs to be a conversation about the "possibility of racial bias" in the case.

"Whether it happened here, I don't claim to be an expert," McCord added.

The lead agent, Claude Thomas, now works for Philadelphia District Attorney Seth Williams.

In an opinion piece published by the Inquirer yesterday, Williams said Thomas "absolutely, unequivocally denied he was asked to, or agreed to, engage in such reprehensible conduct."

Former Auditor General Jack Wagner said he has "serious concerns" about the actions of the legislators, as reported in the Inquirer, and about the lobbyist who "was involved and the charges that were dismissed for that person to set up elected officials."

Lobbyist Tyron B. Ali had been charged with 2,033 criminal counts for stealing $430,000 from a state program "meant for poor children and seniors," according to Kane.

Ali secretly taped conversations with four state representatives from Philadelphia - Ronald Waters, Vanessa Lowery Brown, Michelle Brownlee and Louise Bishop - and Traffic Court Judge Thomasine Tynes, according to the Inquirer.

Waters, Brownlee and Bishop are running for re-election this year with no challengers in the primary or general elections.

Brown has two Democratic primary challengers.

Tynes, who retired in 2012 and was indicted last year in a federal ticket-fixing investigation, is awaiting trial on those charges.

Frank Fina, the assistant attorney general who led the case ultimately dropped by Kane, moved in November 2012 to dismiss the charges against Ali. Kane noted that happened 24 days after she was elected attorney general and 45 days before she took office.

Kane said that "extraordinarily lenient" deal with Ali "crippled the chance of this case succeeding in prosecution."

Fina, who also now works for the Philadelphia District Attorney's Office, wrote an opinion piece in yesterday's Inquirer critical of Kane for hiring lawyer Dick Sprague for a potential defamation lawsuit. He called on Kane to sit down with him and the media to answer questions.

Sprague, in a meeting with the newspaper's reporters and editors Thursday, would not allow Kane to answer questions.

Former state Environmental Protection Secretary Katie McGinty said the controversy shows a need for "an absolute, no loopholes, no exceptions, no asterisks gift ban in public service."

McGinty, speaking with the other candidates at a Philadelphia forum on the May 20 primary election, used the controversy to raise an issue reported by the Daily News last year: Corbett and his wife reported $11,343 in gifts in 2010 and 2011 from lobbyists or business executives with state-regulated businesses.

Public officials in Pennsylvania may accept gifts as long as they are not given to influence their decisions. They must report gifts worth $250 or more, or gifts that add up to $650 or more in a year.

The more-strict Governor's Code of Conduct, instituted in 1980, bans gifts in the executive branch, led by Corbett, from people seeking state business or with business regulated by the state.

The four Democrats agreed with a renewed call by Common Cause Pennsylvania on Thursday for a state ban on gifts to public officials. The good-government group cited the case dropped by Kane when making that call.

The fifth candidate in the Democratic primary, former state Revenue Secretary Tom Wolf, did not attend yesterday's forum.

On Twitter: @ChrisBrennanDN