WASHINGTON, D.C. (CNA/EWTN News) - The Senate failed to bring a bill to block federal funding of Planned Parenthood to the floor on Monday evening, in a much-anticipated vote.

Senate Republicans introduced the bill to defund Planned Parenthood on July 28. An effort to bring the bill to a vote rendered a split of 53-46, gaining support from the majority but falling short of the 60 votes necessary to end debate and bring the bill to the floor.

Two Republicans joined most of the Senate Democrats opposing the bill's passage to the floor -- Sen. Mitch McConnell (R-Ky.) and Sen. Mark Kirk (R-Ill.). Two Democrats joined Republicans pushing to end debate, Sen. Joe Donnelly (D-Ind.) and Sen. Joe Manchin (D-W.Va.).

The chair of the U.S. Bishops' Committee on Pro-Life Activities, Cardinal Sean O'Malley of Boston, had implored the Senate to block federal funds for the organization in an Aug. 3 letter to all senators.

"It has long been troubling to many Americans that the nation's largest abortion network, performing over a third of all abortions, receives over half a billion taxpayer dollars a year," he wrote.

"The most recent revelations about Planned Parenthood's willingness to traffic in fetal tissue from abortions, and to alter abortion methods not for any reason related to women's health but to obtain more 'intact' organs, is the latest demonstration of a callousness toward women and their unborn children that is shocking to many Americans," he continued.

Planned Parenthood has come under fire recently after a series of undercover tapes were released showing top doctors within the organization casually discussing the offering of body parts of aborted babies to harvesters for compensation.

The citizen journalist group Center for Medical Progress had released the videos as part of its "Human Capital" report, a three-year investigative study of Planned Parenthood and its transfer of body parts of aborted babies for money.

Planned Parenthood officials were secretly taped in conversations with actors presenting themselves as representatives of fetal tissue procurement companies, discussing the price per "specimen" for the organs from aborted babies and talking about how to change the abortion procedure to better ensure "intact" body parts.

Religious and civic leaders began calling for the end to federal funding of the organization after the initial videos were released.

Pro-life rallies to defund Planned Parenthood, entitled "#WomenBetrayed," were held in over 60 cities on July 28, coordinated by the pro-life college outreach group Students for Life.

In a July 28 statement, Cardinal O'Malley said the practices described in the videos were further evidence of the "throwaway culture" condemned by Pope Francis.

The Senate's Health and Human Services panel started an investigation into Planned Parenthood, after allegations were made that it broke federal law by selling body parts for "valuable consideration." Two House committees are investigating the organization as well.

Louisiana Gov. Bobby Jindal (R) announced Monday that the state was severing its Medicaid contract with Planned Parenthood.   

The videos have brought to light an "issue that has shaken the moral compass of our society," Sen. Joni Ernst (R-Iowa) stated on the Senate floor Monday afternoon.

"The phrase 'It's a boy' is one we often use in celebrating new life," she said, contrasting this with one of the videos in which a Planned Parenthood clinic worker exclaimed, "Another boy!" when examining the remains of an aborted baby boy in a petri dish.

"Protecting the most vulnerable is an important measure of any society," Ernst continued. "Who do we want to be as a nation? Before us today is an opportunity to vote for legislation that will protect the most vulnerable and women's health."

Planned Parenthood affiliates receive most of their federal funding through Medicaid payments and Title X family planning grants. The 68 affiliates received over $500 million in federal funds in fiscal year 2013 - or 41 percent of its overall revenue - according to Planned Parenthood's annual report.

If the organization is defunded, these funds would go instead to existing health care providers like federal community health centers and hospitals, the bill stipulates.

"Catholic charitable agencies and pregnancy help centers have helped countless pregnant women find life-affirming alternatives to abortion," Cardinal O'Malley wrote in his letter to senators. "Our hospitals and other health facilities are second to none in providing quality health care for women."

The bill ensures "that women can obtain their health care from providers that do not promote abortion," he added.

Federal community health centers do not perform abortions but are required by law to provide an array of services including prenatal care, immunizations, and cancer screenings. They focus primarily on medically-underserved communities and accept payments on a sliding scale from Medicare, Medicaid, and employer's insurance among other sources.

Community health centers already vastly outnumber Planned Parenthood clinics, particularly in states where there are only one or two clinics.

According to the Charlotte Lozier Institute, the research arm of the pro-life group Susan B. Anthony List, the health centers serve almost eight times the number of women per year that Planned Parenthood does. There are over 9,000 community health centers in the U.S. but only 700 Planned Parenthood clinics.

For example, in Alabama there are 131 service sites for community health centers but only two Planned Parenthood clinics. Even in California where there are 115 Planned Parenthood clinics, there are still over ten times as many sites for community health centers - 1,247 in total.

Despite the legislation being blocked, pro-life advocates remained hopeful.

Marjorie Dannenfelser, president of the Susan B. Anthony List, noted in an Aug. 3 statement that Senate support for defunding Planned Parenthood has grown significantly since the last effort to do so in 2011.

"The Center for Medical Progress has released less than half of its damning evidence of brutality and callousness at Planned Parenthood and, as more videos are made public, outrage will surely grow," she said.