Spotlight: Four gun-control measures blocked by U.S. Senate after Orlando shooting

The U.S. Senate on Monday blocked four gun-control measures as the country was still reeling from the deadliest shooting massacre in U.S. history.

The failure to pass any of the measures was widely expected even long before the vote began, since the competing bills, two Democratic and two Republican proposals, were mere repetition of the partisan fight on the gun-control issue.

The votes of all four bills, which focused on whether to expand background check and to block selling of firearms to anyone on federal government's terrorism watch list, were largely along party lines.

Democrats insisted that the sales of firearms should be blocked if there is a "reasonable suspicion" that someone is and will possibly be on the government's terrorism watch list.

In an even longer shot, Democrats also sought a background check for the sales and transfer of guns with a handful of exception, a long-held stance almost unanimously opposed by Republicans in both chambers.

Currently, purchasing firearms at gun shows and on the Internet does not require any background check in the majority of U.S. states.

On the Republican side, GOP lawmakers were pushing forward a measure that would allow the government to delay a gun sale to a suspected terrorist for 72 hours while attorney generals have to seek a court order within the period to permanently block the sale.

Also, instead of imposing an almost universal background check system, Republicans' proposal for expanding background check included providing incentives to share mental health records.

After Monday's failed votes, Senator Susan Collins, a Republican from Maine will on Tuesday introduce a new legislation lauded by some as "a bipartisan compromise" to block suspected terrorists from buying guns.

According to Annie Clark, a spokeswoman for the Maine senator, Collins' proposal would allow attorney generals to block the sale of firearms to people on the "no fly" list or the selectee list.

Unlike the "no fly" list, which bans people on the list from flying from, to and within the United States, people on the selectee list are required to undergo additional security screening at airports without being permanently grounded.

The Senate's latest legislative effort to curb rampant gun violence comes at a time when the country witnessed the deadliest terror attack in the history since the 9/11 terror attacks in 2001.

Forty-nine people were killed and 53 others wounded, on June 12 in a shooting spree at a popular LGBT nightclub in Orlando, Florida.

The gunman, identified by authorities as Omar Mateen of Port St. Lucie, Florida, was found dead inside the nightclub after a shootout with the police.

According to investigators, Mateen legally purchased a handgun and an assault-style rifle weeks before the attack. He was temporarily on Federal Bureau of Investigation's terrorism watch list in 2013.

In recent years, after high-profile mass shootings occurred, such as the carnage at Sandy Hook Elementary School in Connecticut in 2012 which claimed 28 lives, including 20 children, Democrats tried but failed each time to reform the country's flawed gun laws.

In 2013, the Obama administration's gun control initiatives, including expanded background check and bans on assault weapons, were stymied in Congress after staunch opposition from Republican lawmakers and gun-rights lobby groups.

After the shooting spree in San Bernardino, California, last year, in which 14 were killed and 22 more injured, Democrats downgraded efforts to trying to pass a measure to keep people on terrorism watch list from purchasing gun. That legislative effort again failed.

During his presidency, Obama has been confronted with more than a dozen of high-profile mass shootings, and in an interview last year he called the failure to reform U.S. gun laws "one of the greatest frustrations" of his presidency.

"If you ask me where has been the one area where I feel that I've been most frustrated and most stymied, it is the fact that the United States of America is the one advanced nation on Earth in which we do not have sufficient common-sense gun safety laws, even in the face of repeated mass killings," Obama told BBC in July, 2015. Endit