Senate Majority Leader Harry Reid effectively pulled his party’s gun control bill Thursday after a critical background check amendment failed to garner enough support, as he and other Democrats vowed to resume their push for new gun laws in the months ahead.

“Make no mistake, this debate is not over,” Reid said. He acknowledged that he and President Obama had agreed to hit “pause” on the current package, but said the Senate would “come back to this bill” and take up expanded background checks.

At the same time, critics of the legislation vowed to ensure any future proposals protect both “the lives and liberty” of Americans.

Both sides of the debate, it seemed, were gearing up for a protracted legislative battle that could last through the next congressional election. Democrats appeared to acknowledge that the amendment’s failure Wednesday meant they would not be able to pass any gun bill in the short-term, despite initial claims that the mass shooting in Newtown, Conn., might spur a hasty legislative response in Congress.

The amendment that was defeated Wednesday would have expanded background checks to gun shows and Internet sales, while exempting personal transactions. It failed on a 54-46 vote; it needed 60 to pass.

Opponents, which included Republicans and rural-state Democrats, said the measure would infringe on Second Amendment rights by imposing a burden on law-abiding gun owners while doing little to stop criminals. They also repeated the concern that the system could lead to a gun registry, though the amendment language prohibited this.