There will be a round two on gun control legislation.

At least that's what we might glean from Vice President Joe Biden's op-ed Sunday in the Houston Chronicle on the final day of the three-day meeting of the National Rifle Association in Houston.

"For too long, members of Congress have been afraid to vote against the wishes of the NRA, even when the vast majority of their constituents support what the NRA opposes," he said. "That fear has become such an article of faith that even in the face of evidence to the contrary, a number of senators voted against basic background checks, against a federal gun trafficking statute and against other common-sense measures because they feared a backlash."

President Barack Obama said after the defeat of the gun control legislation that he would continue ti push Congress to act in the wake of multiple mass shootings, including the one in Newtown, Conn.

"In the end, I believe we will prevail. And those who wrote off gun safety legislation last month will come to realize that moment wasn't the end at all," Biden wrote. "It was the turning point."

The gun control group founded by former congresswoman Gabby Gifford and her husband, Mark Kelly, launched ads in the states of two senators who against expanded background checks for firearms sales last week.

Americans for Responsible Solutions is targeting Senate Majority Leader Mitch McConnell, R-Ky. and Sen. Kelly Ayotte, R-N.H. with radio ads.

The ads accuse the senators' of favoring the powerful gun lobby instead of supporting popular expanded background checks.

"As Gabby said last week, if we can’t keep our communities safer with the congress we have, we will work to change Congress," said Pia Carusone, the group's executive director. "Senator McConnell and Senator Ayotte turned their backs on their constituents at home in order to do the bidding in Washington of the corporate gun lobby. We’re going to make sure their constituents know that, effective immediately.”

Additional advertising targets – including some thanking senators who their vote – will be released later in the week.

The Democratic Congressional Campaign Committee Monday began a campaign to pressure congressional Republicans to permit a vote on gun control measures.

House of Representatives Republican leaders have said they are weighing how to proceed.

The Democrats' online ads direct backers to a petitition atDCCC.org/background-checks where people can "make their voice heard demanding a vote."

The Senate last week rejected a plan to toughen background checks. Five Democrats opposed the plan, though one was Senate Majority Leader Harry Reid, D-Nevada, who voted no for procedural reasons. Four Republicans voted for it. The plan lost, 54-46.

That didn't take long.

A progressive group released the first ad in a $100,000 campaign against the four Democratic senators who voted against a proposal to expand background checks for firearms sales

The Progressive Change Campaign Committee is targeting Sen. Max Baucus this Sunday in seven papers across his state of Montana -- the Billings Gazette, Butte Montana Standard, Helena Independent Record, Missoulian, Bozeman Chronicle, Kalispell Daily Interlake and Hamilton Ravalli Republic.

The ad -- signed by over 75 gun owners from across the state -- says: "Senator Baucus, it was WRONG to vote 'no' on stopping gun violence. 79% of Montana voters support background checks. Stand with us, not gun manufactures. Support sensible gun laws and keep our families and communities safe."

The Senate will put aside gun control legislation for awhile, Senate Majority Leader Harry Reid said Thursday.

"I've spoken with the president. He and I agree that the best way to keep working toward passing a background check bill is to hit a pause and freeze the background check bill," Reid, D-Nevada, told Senate colleagues.

He insisted the bill will be back, and senators will once again be allowed to offer amendments. He gave no timetable.

"We're going to have time to work on what people want to do before we come back to this," he said. "And it will give  opponents an opportunity to decide what they want to do when we get back on this."

And, he added, "it will give antigun advocates time to make their voices heard by Republican senators."

White House spokesman Jay Carney said Wednesday the president believes the Senate should pass legislation expanding background checks, and that "everybody in the White House is working on this issue from the president on down."

"This was always going to be difficult. We said that from the beginning," he said. "The reason why these common sense provisions aren't law already is because they are difficult. And there is no question that the path to 60 in this case is difficult, but it is not unachievable."

Carney said senators who vote against the legislation should explain why.

"If you are opposed to this legislation, you should obviously explain why, and you should explain why you... are against something that 90 percent of the people are for, that vast majorities of the people in your state support. Members of the Senate ought to ask themselves, who are they representing?"

"There aren't too many issues in America of significance that have 90 percent support from the American people. There aren't too many issues that rise to the prominence that this has risen to that enjoy that kind of broad-based support from Republicans, Democrats, independents, gun-owners, non-gun-owners, urban dwellers, people who live in rural areas. And so you have to wonder why this is so hard, why, you know, who -- the senators who -- who are voting no, if they vote no, represent the very people who have said overwhelmingly that they want this done. And that's -- that's a shame. But we -- we believe -- we know there's a vast majority of the American people who support this. And we believe that there should be 60 votes in the Senate to support it."

Senate Majority Leader Harry Reid has long been a gun rights supporter, but said Wednesday he'll back the assault weapons ban up for a Senate vote later today.

"I will vote for the ban because maintaining law and order is more important than satisfying conspiracy theorists who believe in black helicopters and false flags," he told Senate collagues. "And I will vote for the ban because saving the lives of young police officers and innocent civilians is more important than preventing imagined tyranny."

Reid noted, "I am a strong supporter of Americans’ right to keep and bear arms. That’s how I earned a B grade from the National Rifle Association. When I was a 12-year-old little boy in Searchlight, Nevada, my parents sent away for a 12-gauge shotgun from the Sears catalogue. And I carried a handgun when I served on the Capitol Police force," Reid recalled. 

"Where I come from, people own guns as a matter of course for self-defense and for hunting," said the Nevada Democrat, "but I have always had trouble understanding why people need assault weapons to hunt or to protect their homes.

"When the assault weapons ban came before the Senate for a vote in 1993 I called my friends in Nevada to ask their opinion on the legislation. One friend said he believed it was impossible to define what an assault weapon was. That seemed reasonable to me, and so I voted against the ban."

Here's more from his Senate speech:

Supports of the Manchin-Toomey background check compromise lost a crucial vote as Sen. Dean Heller, R-Nevada, announced he was opposed.

That will make it even more difficult for the effort to get the 60 votes needed to pass. A vote is scheduled to begin at 4 p.m.

Here's Heller's statement:

"When it comes to national policy choices on issues such as Constitutional liberties, gun violence and public safety, the stakes could not be higher. The enormity of this issue has weighed heavily on me. While I was home this past weekend, my family and I ate at the Carson IHOP where four people lost their lives and several were injured. The survivors of that senseless shooting in the morning hours of September 6, 2011, deserve this debate.

“I believe very strongly that our current background check system needs strengthening and improving, particularly in areas that could keep guns out of the hands of felons and the mentally ill.  At the same time, I cannot support legislation that infringes upon the Constitutional right to keep and bear arms.  Despite the good faith efforts of Senators Manchin and Toomey, the onerous paperwork and expansion of federal power mandated in this legislation are too great of a concern. I believe that this legislation could lead to the creation of a national gun registry and puts additional burdens on law-abiding citizens. For these reasons, I cannot vote for this legislation."

The Senate plans to begin voting at 4 p.m. Wednesday on nine amendments to its gun safety bill, amendments that deal with a wide range of gun control and gun rights issues.

Each vote will last 10 minutes, and there will be two minutes of debate equally divided between each side before each vote.

It's not clear when a final vote on the bill will be taken.

First vote is expected to come on a stronger background check measure, a compromise pushed by Sens. Joe Manchin, D-W.Va., and Pat Toomey, R-Pa.

Then will come amendments on gun traffricking, extending conceald carry laws, banning assault weapons, limiting the size of magazine clips and more.

Two House of Representatives lawmakers have introduced legislation to strengthen gun background checks, the House version of the Senate compromise on the issue.

Reps. Peter King, R-N.Y., and Mike Thompson, D-Calif., are lead sponsors. The Senate is debating the measure this week, and a vote is expected later in the week. 

Thompson and King released a joint statement: “Background checks are the first line of defense against criminals and the dangerously mentally ill getting guns. This bill is comprehensive, it is enforceable, it will save lives, and it will protect the rights of law abiding Americans to own guns. It’s time for Congress to act. The American people are getting a vote in the Senate. They deserve one in the House."

Whether that vote will be held in the House remains uncertain.

Here's more from Tuesday's news release: