(CNN) -- The U.S. Senate will begin voting on amendments to gun legislation on Wednesday, including the leading proposals for tighter restrictions spurred by the Connecticut school massacre in December.
Senate Majority Leader Harry Reid said the list of first votes would include the bipartisan yet controversial agreement on expanding background checks proposed by Sen. Joe Manchin, D-West Virginia, and Sen. Pat Toomey, R-Pennsylvania.
Also up in the first round will be Sen. Dianne Feinstein's proposal to ban the sale of semiautomatic firearms modeled after military style assault weapons.
President Barack Obama and many Democrats support a renewed assault weapons ban and an expansion of background checks as well as other measures before the Democratic-led Senate.
A proposal by Republican Sen. John Cornyn of Texas on a proposal to make state concealed weapons permits acceptable throughout the country will also be considered.
Other votes include a bipartisan amendment dealing with mental health and five other measures.
Each amendment needs 60 votes to pass and the first votes will start in the late afternoon.
Debate on the Senate gun bill is expected to last at least two weeks.
Obama and others also have been highlighting daily gun violence in America in their appeal to lawmakers for stricter limits.
Many in Washington have coalesced around expanding background checks conducted on gun sales by the FBI. But settling on the exact wording of such a step has been difficult in a sharply divided political climate.
The deliberative steps by lawmakers proved to be too good to pass up for the folks at "Saturday Night Live."
Last weekend's opening skit begins with President Barack Obama praising the Senate.
"As you know, over the past few months I have made gun control legislation a top priority for my administration, which is why I am so excited to announce that this week the Senate voted 68-31 to begin debating the idea of discussing gun control. Let me say that again, they've agreed to think about talking about gun control. Amazing."
The president then introduces Manchin and Toomey to explain their background check legislation.
"If our bill passes, no individual will be able to purchase a handgun from a private dealer without being asked 'Are you a good person?' As well as the follow up question, 'Seriously, are you?'" Toomey says.
"Also, we're very proud of this, we were able to ban AK-47s from all coin-operated vending machines."
Manchin concludes: "Look, is this bill what we wanted? No. Is it what the NRA wanted? No. But does it at least help in some small way?"
After a pregnant pause, both men admit the answer is no.
Few amendments may pass
While Democratic leaders are expressing optimism they'll get enough votes to pass the Manchin-Toomey amendment, a CNN tally of senators indicates the measure is probably in trouble unless several undecided Democrats and Republicans -- mostly from conservative states -- throw their support behind it.
The proposal would extend background checks to include gun shows and Internet sales.
Reid said last month that Feinstein's proposal, which was approved by the Senate Judiciary Committee on a Democratic party-line vote, has no chance of passage. Yet, he wanted to ensure it received a vote as an amendment rather than join it to a package of measures approved by the panel that would toughen laws on gun trafficking and straw purchases.
The powerful National Rifle Association, the leading advocate on gun rights, fiercely opposes the Feinstein proposal as well as the Manchin-Toomey compromise. It supports the measure on concealed permits.
Speaker John Boehner has said the House would look at anything passed by the Senate, but is not committing to any plan or votes.
Polls support background checks
The drive for tougher gun control was spurred by the massacre of school children and educators by a lone gunman in the quiet community of Newtown, Connecticut, just before Christmas.
Polls since show a preference among Americans for some type of initiative to stem gun violence.
In a CNN/ORC International poll released last week, 86% of Americans say they support some form of background checks.
However, a majority of Americans also fear that increased background checks would lead to a federal registry of gun owners that could allow the government to take away legally owned weapons.
The 86% figure from the CNN/ORC poll is in line with just about every other national survey released over the past couple of months, which found support for increased background checks hovering around the 90% level. And the CNN survey, along with the previous polls, found no real partisan divide, with very strong support for the checks from Democrats, Republicans, and independents.