WAKARUSA, Ind. (AP) — President Barack Obama said this week he’s determined to get an overhaul of the health care system before the end of the year and, if necessary, without bipartisan support.

His comments on Wednesday reflected a growing sense among Democrats that they may have to carry the legislation to expand coverage and try to control medical costs with votes from lawmakers of their own party – or at best a handful of Republicans.

Visiting economically stressed Indiana to announce $2.4 billion in taxpayer grants for electric cars and tens of thousands of jobs, Obama pledged successful conclusion of the health care overhaul that he argues would stabilize the nation’s fiscal health.

“I promise you, we will pass reform by the end of this year because the American people need it,” the president said.

That will take some doing, since action on legislation in the House and Senate has been slowed by divisive policy arguments. Republican leaders oppose the Democrats’ approach, and they’re saying Congress should start over. But in an interview after his speech, Obama said he is not wedded to a bill with Republican as well as Democratic support.

He said he is encouraged that a small group of three Democratic and three Republican senators on the Finance Committee continue to negotiate, but signaled impatience with protracted talks that haven’t yet produced legislation.

“Sometime in September we’re going to have to make an assessment” about whether to keep trying to negotiate with Republicans, he told MSNBC.

Obama said he “would prefer Republicans working with us” but that getting his main priorities for a health care overhaul are more important. It represents a marked change from the emphasis Obama placed on bipartisanship when he launched his campaign for a health care overhaul at a White House summit in March.

The president’s shift is being echoed by Democratic senators.

“The time is closing in,” said Sen. Jay Rockefeller, D-W.Va. “We cannot finish this year without passing major health care reform. It’s our sacred duty to the American people.”

Rockefeller said negotiations with Republicans have only resulted in a bill that “gets weaker, and weaker, and weaker.”

“Everything is being focused on will three Republicans cooperate, or will they not?” Rockefeller said.

With the Senate expected to begin a monthlong vacation at the end of the week, Obama invited the six bipartisan negotiators to a White House meeting on Thursday.

Meanwhile, Republican and Democratic leaders traded accusations about the sometimes aggressive protests that have occurred over health care in a number of states. On several occasions in recent days Democratic lawmakers have been mobbed or shouted down by sign-waving activists who Democratic leaders claim are being organized by outside groups and lobbyists.

Republican Party Chairman Michael Steele defended the activism, even as he denied the party was organizing it.

“We are not inciting anyone to go out and destruct anything. We’re encouraging people to go and visit their congressman or their senator,” Steele told reporters on a conference call. “We’re not organizing the town halls, the congressmen and the senators are. And as citizens they have a right to go and express their points of view.”

Obama referenced the opposition in a fundraising e-mail sent by his political group, Organizing for America, and asked his supporters to attend events to show their support for his health care plans.

“There are those who profit from the status quo, or see this debate as a political game, and they will stop at nothing to block reform,” he said.  “They are filling the airwaves and the Internet with outrageous falsehoods to scare people into opposing change.”

Democrats will need 60 votes to overcome parliamentary delaying tactics and pass a bill in the Senate.  While there are 60 Democratic senators, two have been absent because of illness, and not all Democrats support the legislation that has emerged thus far from committee.

Democratic leaders could resort to a maneuver that lets them pass a budgetary bill with a 51-vote majority, but it comes with a risk: Large parts of the health care legislation could be stripped away on the Senate floor if they don’t directly relate to spending or revenues.  Among the provisions likely to be targeted are consumer protections such as prohibitions to keep insurance companies from discriminating against patients in poor health.

Rockefeller said Democrats “coming together will be the requirement we go through to get a good bill.”

Sen. Sherrod Brown, D-Ohio, suggested that fellow Democrats would be taking a risk if they defy their party leadership on procedural votes that could snarl the health-care bill.

“I don’t think there’s any Democrat, on a procedural vote, who wants to be on the wrong side of history,” he said. “I think, in the end, there will also be a handful of Republicans who don’t want to be on the wrong side of history.”

Associated Press writer Ricardo Alonso-Zaldivar reported from Washington. AP writers David Espo and Erica Werner in Washington contributed to this report.

Photo: President Barack Obama