Obama supporter Bill Bradley identified full disclosure as an issue relating to the Clintons.

(CNN) – Three supporters of Sen. Barack Obama took the opportunity, in a conference call with reporters Thursday, to suggest Sen. Hillary Clinton and former President Bill Clinton have not been candid with the American public.

Texans “are gonna want people to shoot straight. They’re gonna want straight answers,” said Texas State Senator Kirk Watson.

Citing Sen. Clinton’s latest campaign theme focused on ‘solutions,’ Watson also said residents of his state are going to asking whether Clinton’s health care plan is actually offering solutions or, instead, raising more questions – including how Clinton would enforce the individual coverage mandate in her plan.

Asked by a reporter about an ongoing issue regarding candidates releasing their tax returns, former U.S. senator Bill Bradley linked Sen. Clinton’s refusal to release her tax returns with her failure to disclose what the individual coverage mandate in health care plan would cost.

Representative Jim Cooper of Tennessee followed Bradley saying memos relating to Sen. Clinton’s earlier effort to reform health care during her husband’s administration also have not been disclosed.

“And, as long as we’re on the issue of full disclosure, President Clinton also hasn’t revealed who were the contributors to his presidential library while he was still in office,” added Bradley.

Texas is set to hold its presidential primary on March 4 and Clinton must do well there to keep alive her bid for the Democratic nomination. In 2006, Texas had the highest rate of uninsured residents of any state in the nation, according to the American College of Emergency Physicians.

Sen. Clinton has recently sought to contrast her health care plan with Sen. Obama’s during campaign stops and debates. Former President Bill Clinton also attacked Obama’s health care plan as inadequate while in Texas Friday.

The conference call was held on the same day that Clinton released a new radio ad in Wisconsin touting her health care plan. Wisconsin holds its presidential primaries on March 19.

–CNN Associate Producer Martina Stewart

Bill Bradley is backing Obama for president.

WASHINGTON (CNN) — Democrat Barack Obama has won the backing of former Sen. and 2000 Democratic presidential hopeful Bill Bradley, the Illinois senator's campaign announced Sunday.

“Barack Obama is building a broad new coalition that brings together Democrats, Independents, and Republicans by once again making idealism a central focus of our politics,” Bradley said in a statement released by Obama's campaign.

“Because of his enormous appeal to Americans of all ages and backgrounds, Obama is the candidate best positioned to win in November," he added. "Barack knows above all that unless people can once again believe in our democracy, we won’t be able to do the things that need to be done on health care and education or to break our dependence on foreign oil."

The endorsement comes two days before the crucial presidential primary in New Hampshire. The latest CNN/WMUR poll shows a dead heat in the Granite State between Obama and Hillary Clinton, each drawing 33 percent among likely Democratic voters there.

– CNN Ticker Producer Alexander Mooney