President Obama tonight honed a defense of his administration's controversial health care law, calling pledges by his Republican rivals to roll back the legislation an affront to women.

"Because of this law, preventive care is now covered and, yes, that includes preventive care for women: check-ups, mammograms, birth control," Obama told an applauding crowd of more than 750 campaign donors in Houston.

"So when you see politicians trying to take us back to the days when this care was more expensive and harder to get for women - and I know you're seeing some of that here in Texas - you just remember we can't let them get away with it," he said.

The comments on women and the health care law are a notable, new twist in Obama's campaign stump speech.  Previously, Obama has tended to focus only on provisions of the law that banned preexisting condition restrictions,  allowed young adults to remain on their parents' insurance plans and expanded prescription drug coverage for seniors.

They also came the same day his administration decided to cease funding a state Medicaid program for low-income women in protest of a decision by the Republican-dominated Texas government to block Planned Parenthood and other affiliates from receiving some of the federal cash.

"This is not just a political debate. This is the defining issue of our times," Obama said later of the ideological debate with Republicans over issues like health care. "A make or break moment."

The event at Minute Maid Park, home of the Houston Astros baseball team, was one of two evening fundraisers at which Obama was expected to net at least $2.8 million combined, according to a campaign official.

The biggest checks of the night for Obama and Democrats were cut at an intimate $35,800-per-person reception with 70 donors at the private River Oaks home of Dr. Dina Alsowayel, associate director of the women's studies program at the University of Houston, and Tony Chase, a University of Houston law professor and former Harvard Law School classmate of Obama.

Proceeds from both events - Obama's 35 th and 36 th of the year - go to the Obama Victory Fund, a joint account of the Obama Campaign and Democratic National Committee, which funnels the first $5,000 of an individual's contribution to the president and the remainder, up to $30,800, to the DNC.

Harris County, which includes Houston, is friendly turf for Obama in an otherwise red state.  Voters there backed him by more than 18,000 votes over John McCain in 2008, though Obama ultimately lost the state by 946,000 votes.

Still, Texas is among the most generous states to Obama's re-election effort - and more generous to Obama than to any of the other remaining Republican candidates, according to the Center for Responsive Politics.

Obama has raised more than $3.45 million in contributions from Texans through March 5, according to Center for Responsive Politics analysis of Federal Election Commission data.  GOP frontrunner Mitt Romney has raised $3.2 million, Rep. Ron Paul has collected $1.5 million and Newt Gingrich has received $920,000.