Rivalry heats up for Cahill and Baker

With both challengers chasing disaffected voters, Cahill has attacked Baker for his involvement in the financing of the Big Dig and for his views on health care. Baker returned fire yesterday by challenging Cahill’s fund-raising methods and the transparency in his office, calling for new disclosures on donors connected directly or indirectly with business interests before the treasurer.

Polls suggest that Patrick’s best chance to win will be if both challengers fight to the end, splitting the anti-incumbent vote, which made the Baker-Cahill duel inevitable, said Maurice Cunningham, professor of political science at the University of Massachusetts Boston.

“One of them needs a clear field, obviously, and the quicker you can downgrade the other guy, the quicker you can turn on a very vulnerable incumbent,’’ Cunningham said.

Patrick, who returned Tuesday from his trip out West, has hardly stayed on the sidelines, going after both opponents in recent days with new aggressiveness. Yesterday, Patrick took aim at Cahill; the treasurer has defended his recent criticism of the state’s health care program by saying he had been warning of fiscal problems since 2008.

“That last comment is B.S.,’’ the governor said, according to State House News Service. “I’m sorry to be so blunt, but I don’t think the treasurer, due respect, has expressed any concerns about health care reform until a political season came around.’’

But notable in recent days have been the sharp exchanges between Baker and Cahill, as the Republican Party begins targeting Cahill more directly as a potential spoiler.

Yesterday, Baker criticized Cahill’s practice of raising campaign contributions from firms that do business with the treasurer’s office or have ties to such firms and the lack of information about many donors’ occupations on his campaign committee reports.

Baker cited a Sunday Globe report that Cahill had accepted more than 200 donations from employees of firms that handle real estate holdings of a Boston-based investment firm that has been allotted $500 million in state pension funds to manage since Cahill became treasurer in 2003. Baker called for more public disclosure of unregulated placement agents working for firms seeking to manage pension funds.

Cahill has repeatedly denied any connection between political contributions and the selection of vendors or state pension fund managers. Michael Travaglini, executive director of the state Pension Reserves Investment Management Board, dismissed Baker’s criticism.

“This is really silly season,’’ he said. “What they’re asking us to do in their release, we have been doing for 10 years, which, if Charlie Baker knew as much about state government as he purports, he would understand.’’

Cahill’s campaign said yesterday that Baker was trying to change the subject because in his own campaign he has raised large sums from the health care industry and companies that did business with Harvard Pilgrim Health Care, where Baker was chief executive for a decade.

But another thorny potential political problem surfaced for Cahill yesterday: The Securities and Exchange Commission charged that an executive of a Texas securities firm, which helped underwrite at least $14 billion of Massachusetts municipal securities, violated federal “pay to play’’ rules with campaign contributions to Cahill.

Much of the crossfire has been over Cahill’s criticism of the state’s health law. The Globe reported yesterday that Cahill’s critique does not square with an official statement on state finances that he signed for a $538 million bond offering in early March and which makes no reference to his concerns.

The Republican Governors Association, newly active in the race, circulated the story, and spokesman Tim Murtaugh said, “Over the past few days it’s become clear that Tim Cahill thinks he can get away with anything and not get caught.’’

About two hours earlier, Bradley H. Jones Jr., Republican leader in the Massachusetts House, wrote a blog item calling Cahill’s comments “political posturing’’ that reflect “a clear disconnect with truth and reality.’’

“A lot of us voted for [the health care law], and he’s essentially thrown us all under the bus,’’ Jones said in an interview.

Cahill stood by his comments, contending the state’s health care program is propped up by federal funds and cannot sustain spiking costs in the state’s Medicaid program.

“Obviously, everyone’s throwing bricks at me because I’m out in front on this health care issue,’’ Cahill, a former Democrat, said yesterday. “A lot of people are agreeing with what I say.’’

Cahill also produced a little-noticed article he wrote for Commonwealth magazine in January that laid out his concerns.

“I understand nobody was listening to me a month or two months ago,’’ Cahill said. He said they are responding now because “I’ve hit a nerve.’’

Earlier this week, however, Michael Widmer, president of the business-funded Massachusetts Taxpayers Foundation, said Cahill has exaggerated the issue by confusing Medicaid costs with those actually attributable to the 2006 law. The watchdog group last fall issued a report stating the increased annual costs of the program were in line with projections at the time it was passed.