The US Senate voted down four competing gun control proposals, allowing Democrats and Republicans to stake out political turf around a controversial, emotional issue that promises to play big in a campaign year.

The votes, which fell mostly along party lines, came as the debate over gun laws has been reinvigorated following the recent mass shootings at an Orlando, Florida, nightclub popular with the gay community.

Despite both parties presenting proposals to tighten certain aspects of gun laws, attempts to craft any compromise ran aground last week leading to today's series of votes that served as a way for both sides to send political messages.

Variations of all four proposals considered Monday already failed to pass the Senate in December following the deadly mass shooting at the hands of Isis (Islamic State) sympathisers in San Bernardino, California.

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Democrats charged that today's votes fit a pattern of Republicans giving in to the demands of the National Rifle Association following tragic shooting incidents despite polls showing support for stricter gun laws.

"Senate Republicans ought to be embarrassed, but they're not, because the NRA is happy," Senate Minority Leader Harry Reid.

Senate Majority Leader Mitch McConnell, accused Democrats of pushing a "partisan agenda".

In the week since the most recent mass shooting, both Democrats and Republicans have repeatedly stated that terrorists should not be able to purchase guns.

But there are substantive differences between the proposals offered by both sides - all of which required 60 votes to advance in the Senate.

The Senate voted 47 to 53 to reject a measure from Senator Dianne Feinstein, to let the attorney-general deny firearms and explosives to any suspected terrorists. Senator Heidi Heitkamp of North Dakota was the sole Democrat to vote against the measure, while Republican senators Kelly Ayotte of New Hampshire and Mark Kirk of Illinois, both of whom face tough re-election contests, voted for it.

The Senate, on a 53 to 47 vote, also rejected a Republican alternative from Senator John Cornyn, that would allow authorities to delay a gun sale to a terrorism suspect for three days or longer if a judge ruled during that time that there is probable cause to deny the firearm outright.

Two Democrats, Senators Joe Manchin of West Virginia and Joe Donnelly of Indiana, backed the measure. But three Republicans - Senators Jeff Flake of Arizona, Kirk and Susan Collins of Maine voted against Cornyn's amendment.

Both provisions contained language to alert authorities if anyone who has been on a terror watch list in the last five years tries to buy a gun. Such a provision might not have prevented the Orlando shooter from buying the weapons he used in the nightclub massacre, but it would have let authorities know when he purchased the firearms.

Republicans argued that Feinstein's proposal doesn't do enough to protect against situations where someone mistakenly on a terror watch list, or mistakenly suspected of links to terror groups, would be denied their Second Amendment rights.

Democrats countered that the time limitations in Cornyn's alternative would make it functionally impossible to actually prevent suspicious individuals from purchasing firearms.

A handful of Republicans have also voiced their own criticism of Cornyn's legislation. Ayotte said that she would support the procedural votes on both the Cornyn and Feinstein measures - not because she thought either posed a satisfactory solution, but "to get to this debate, because I want a result," she said.

Ayotte was working with Collins over the last week to try to come up with a compromise proposal. That proposal would prevent people on two subsets of the FBI's database of suspected terrorists - the "No Fly List" and the "Selectee List" - from buying guns and alert the FBI if someone on those lists in the previous five years tried to purchase weapons.

But Democrats said that Collins' proposal was too narrow and would allow too many potential terrorists to fall through the cracks.

"Her alternative is not enough to close the loophole that creates this terror gap," Feinstein said.

The Senate also rejected, on a 44 to 56 vote, a measure from senators Chris Murphy, Cory Booker and Charles Schumer that would expand background checks for anyone trying to purchase a firearm, including at a gun show or online.

It was a more expansive version of a compromise measure from senators Joe Manchin and Pat Toomey, that sought to expand background checks in 2013 after the mass shooting at the Sandy Hook school in Newtown, Connecticutt. Their proposal never gained the needed support.

Republicans objected to the breadth of the Murphy-Booker-Schumer proposal, which would require a background check for almost any sale or transfer of a firearm.

Instead, Republicans backed an alternative from Senator Charles Grassley that would increase funding for the government to run background checks without expanding them. It failed on a 53 to 47 vote.

Democrats also objected to Grassley's amendment they said it could give people involuntarily committed to a psychiatric institution for a mental illness the right to buy a gun once they are released.

The Obama Administration said it supported the Feinstein and Murphy-Booker-Schumer amendments.

Last week, Democrats took their frustrations to the Senate floor in a near 15-hour filibuster, led by Murphy, in which they demanded votes on their two proposals.

They credited the display with bringing about the votes. Republican leaders, meanwhile, derided them for staging a "campaign talk-athon" on the Senate floor that only slowed things down.

But Democrats are counting the votes as an incremental victory in their campaign to build a political movement to demand gun control measures.