DENVER — President Barack Obama is planning to visit Denver on Wednesday to discuss gun control with local law enforcement officials, the White House announced on Saturday.

The announcement comes after a wave of rallies across the country sought to increase pressure on Washington to act.

Obama is scheduled to visit with local law enforcement and community leaders to discuss the state’s new gun control laws that were signed into law 10 days ago.

As momentum behind and public support for gun control laws appears to be waning, the president summoned some of the emotion he expressed just days after December’s mass shooting in Newtown, Conn. and pushed back at a POLITICO report this week that the moment for action on the issue appears to have passed.

“I read an article in the news just the other day, wondering is Washington, has Washington missed its opportunity because as time goes on after Newtown, somehow people start moving on and forget,” Obama said in the East Room, flanked by relatives of gun violence victims and advocates for stricter gun control. “Let me tell you, people here don’t forget.

“The notion that two months or three months after something as horrific as what happened at Newtown happens, and we’ve moved on to other things? That’s not who we are. That’s not who we are. I want to make sure every American is listening today. Less than 100 days ago that happened. And the entire country was shocked. The entire country pledged we would do something about it and this time would be different. Shame on us if we forgot. I haven’t forgotten those kids. Shame on us if we forgot.”

The White House has been lowering expectations about a package of gun control legislation, admitting that even getting a universal background checks measure passed would be a real victory.

Colorado lawmakers have already passed such a law and another banning magazines larger than 15 rounds.

On Thursday, two of the remaining gun control measures, bills limiting online concealed carry permitting and restricting guns from domestic violence offenders, both cleared House committee hearings with far less debate and protest than that generated by the bills signed into law already.

It’s uncertain where a magazine ban would be part of the gun legislation that will be introduced first in the Democratic-led Senate; it’ll need to pass out of the Senate with bipartisan support in order to have a chance of winning approval in the Republican-controlled House.

Support for gun control dropping

Polls conducted over the past few weeks suggest that more than three months after the Newtown killings, public backing for major new gun laws has dropped.

Obama noted the political challenge as well as the poll numbers.

“There are some powerful voices on the other side who are interested in running out the clock, or changing the subject,” the president said, adding that “their assumption is that people will just forget about it.”

Along with the White House event, the national day of action included rallies and other gatherings in cities across the country by supporters of new gun legislation.

“There are 80 million moms in this country,” said Shannon Watts, founder of Moms Demand Action for Gun Sense in America, after the White House event. “This is a non-partisan issue. It doesn’t matter if you’re a Republican or if you’re a Democrat. We need to come together under one umbrella and say ‘enough’.”

Bloomberg group holds rallies across the country

In addition, Mayors Against Illegal Guns, the group founded and funded by New York City Mayor Michael Bloomberg, sponsored rallies across the country, including one in the Golden park where Nathan Leon, an unsuspecting pizza delivery driver, was apparently murdered weeks ago by Evan Ebel.

“We are calling on our federal delegation to take action,” said Golden Mayor Marjorie Sloan. “Here in Colorado, we’ve taken action, but we need our federal leaders to take the initiative too.”

This week, Bloomberg’s group launched a $12 million ad campaign targeting members of Congress in 10 states to act on the legislation backed by Obama and approved by the Senate Judiciary Committee on mostly partisan lines.

Another proposal passed by the committee — a ban on semiautomatic firearms that are modeled after military assault rifles — already appears doomed.

Senate Majority Leader Harry Reid dropped the ban — proposed by Sen. Dianne Feinstein, D-California — from the package going to the Senate floor because it lacked enough support to overcome a GOP filibuster. Reid said it can still be offered as an amendment to force a vote, as sought by Obama and Feinstein.

Obama rejected arguments by opponents of the legislation that the measures would strip Americans of their constitutional right to bear arms.

“What we’re proposing is not radical. It’s not taking away anyone’s guns rights,” the president said in warning legislators against getting “squishy because time has passed and maybe it’s not on the news every day.”

Instead, he said, it’s time to demonstrate that the American character includes being “willing to follow through on what we say is important.”

In addition, some deep-pocketed Democratic donors are threatening to cut off Democratic lawmakers who don’t vote in favor of gun control measures in Congress, according to a report late Thursday by the Washington Post.

Newtown documents released

Police released new documents Thursday related to the Newtown shootings that say police found more than 1,600 rounds of ammunition in the home where Lanza killed his mother with one of her own guns, shooting her in the forehead as she lay in bed.

Lanza then went to the elementary school, shooting his way inside and opening fire on classrooms with a semiautomatic rifle before killing himself to end the rampage, which lasted less than five minutes, the documents showed.

“This is exactly why we need to ban high-capacity magazines and why we need to tighten our assault weapons ban,” Connecticut Gov. Dannel Malloy said Thursday. “I don’t know what more we can need to know before we take decisive action to prevent gun violence.”

After the Newtown shootings, some states — including New York — passed tougher gun laws.

While the fervor for stronger legislation was high in the immediate aftermath of the shootings, a CBS News survey released this week indicates a 10-point decrease in support of stricter gun laws, from 57% immediately after the Newtown shootings to 47% now.

That poll was in line with a CNN/ORC International survey released last week that indicated a 9-point drop in the percentage of Americans who favor major restrictions on guns or an outright ban on gun ownership, from 52% following the shootings to 43%.

Other polls have shown changes in the same downward direction.

“Opinion on gun control was fairly steady over the past few years, but seemed to spike after the Connecticut shootings,” CNN Polling Director Keating Holland said. “The big question is whether support for major new gun laws has simply dropped back down to that previous level or whether the slide will continue even further.”

He noted that the biggest drop came among two specific demographics — older Americans and people who live in rural areas.

“In the immediate aftermath of the shootings in Connecticut, the number of rural Americans who supported major gun restrictions rose to 49% but now that support has dropped 22 points,” Holland said. “Support for stricter gun laws dropped 16 points among Americans over 50 years old in that same time.”

However, Obama noted that polls also show strong support across the spectrum, including among gun owners, for expanding background checks to prevent firearms from ending up in the hands of the mentally ill and criminals.

The CBS poll showed that 90% of respondents agreed, and the president noted that support, asking Thursday “how often do 90% of Americans agree on anything?”

He urged people to find out where their congressional representatives stand on the gun legislation, adding that if a legislator isn’t “part of the 90%, ask why not.”

CNN contributed to this report.