Like abortion is to conservatives, gun control is liberals’ white whale. The issue stokes heated passion among rank-and-file party voters, but often proves to be treacherous in swing states. As Democrats become increasingly determined to push a gun control agenda, they will have to ask themselves how far are they willing to go and how much political risk they wish to take. Anti-abortion Republicans who stopped asking themselves those kinds of questions in the Obama years paid a price.

Gun control has returned to the top of the Democratic wish list after several years of being downplayed, if not outright abandoned, as an issue. John Kerry famously went goose hunting in the waning days of his 2004 presidential bid. During his first presidential campaign, Barack Obama expressed support for the June 2008 District of Columbia v. Heller Supreme Court decision striking down a municipal ban on handguns and asserting an individual right to bear arms. Mass shootings in his first term, such as the 2012 Aurora movie theater rampage, were not followed by any significant effort to reinstate the Clinton-era assault weapons ban that expired on President George W. Bush’s watch.

The sotto voce approach worked, helping Obama win twice in swing states with significant gun ownership, including Colorado, Iowa, Nevada and New Mexico. But since the emotional trauma of the December 2012 Sandy Hook elementary school massacre, most prominent Democratic Party leaders are no longer willing to hold their tongues.

However, President Obama and other leading Democrats have been careful to propose measures that poll well. The assault weapons ban ­– which has registered mixed poll numbers – remains unmentioned, even in Obama’s rallying cry on last week’s New York Times op-ed page. An outright ban on handguns – the weapon of choice in the vast majority of gun deaths – is completely off the table.

Obama’s emphasis is on universal background checks – so the 22 percent of gun purchases from unlicensed dealers could no longer skip that step. Ninety-two percent of Americans support that position in the most recent CBS/New York Times poll. His earlier call to ban gun sales to people on the terrorist watch list was backed by a similarly strong 83 percent in a December Quinnipiac poll.

By pursuing measures that yield the broadest measure of public support, Democrats are on safe political ground, but they are not focused on measures that would prevent huge numbers of fatalities. In response, gun rights conservatives howl that most of the mass shootings cited by Obama as the impetus for action didn’t involve flawed background checks or people on the terrorist watch list.

The dueling arguments are reminiscent of the “partial-birth abortion” fault lines of the 1990s and 2000s, which should unnerve gun control and gun rights supporters alike.

Ever since Roe v. Wade, anti-abortion conservatives have sought to chip away at abortion rights by pursuing restrictions. Soon after Republicans seized control of Congress in 1995, they set their sights on banning a particular late-term abortion procedure that anti-abortion activists dubbed “partial-birth” to suggest infanticide.

Activists promoted the story of a formerly pro-choice nurse who said she was horrified after participating in the procedure, prompting Congress to receive her graphic testimony. By 1996, even though most Americans called themselves “pro-choice,” and despite the dubious constitutionality of the proposal, a solid majority of voters supported a legislative ban (though poll questions often glossed over the most controversial element in the bill: the lack of an exception for when the mother’s health is in jeopardy).

Much like how gun rights proponents argue that tighter background checks wouldn’t affect most shootings, pro-choice activists gamely tried to defuse public outrage by explaining that extremely few women had late-term abortions and only did so when medically necessary.

To no avail. The poll numbers prompted many swing-district Democrats to ditch their pro-choice allies. Republicans were able to pick off about 70 House Democrats and twice put the bill on President Bill Clinton’s desk. While Clinton won his veto battles in the Senate, Republicans were winning the public opinion war. Once George W. Bush was in the Oval Office, the bill passed with ease. And once Bush replaced pro-Roe Supreme Court Justice Sandra Day O’Connor with Samuel Alito, the law could be upheld.

The decade-long “partial-birth” fight offers a path to victory to those now hoping Congress can eventually be moved to accept universal background checks: ignore the broader political landscape and the current distribution of power in Washington, shelve your larger ideological ambitions, lock in on a popular yet narrow provision – avoiding any swing state blowback in presidential election years – and push the public’s emotional buttons until you eventually drive a wedge through the opposition party.

But if there are lessons for gun control advocates to take from the pro-life movement’s persistence, there is a cautionary tale as well.

The national partial-birth abortion ban was a capstone achievement after years of successful battling for various abortion restrictions at the state level. And yet, there are still a lot of abortions in America, about 1 million per year.

That number has steadily declined from 1.5 million in 1991. But since abortion is down in states with weak and strong restrictions, better contraception and lower pregnancy rates are more likely drivers of the decline than legal barriers, most of which only impose delays. Certainly the federal partial-birth ban has little to do with it; only about 2,000 abortions per year involved the procedure when it was legal.

As a result, pro-life adherents are not very content with their victories. They don’t want fewer abortions. They want no abortions. And frustrated conservative politicians have been more willing to admit their desires, despite the political risk.

In 2012, two Republican Senate candidates in red states lost winnable races after controversial defenses of their opposition to an abortion exception for rape victims. In the current presidential race, an undeterred Sen. Marco Rubio assured pro-life voters that he "never advocated" for a rape and incest exception, and said that he would sign "any legislation that reduces the number of abortions" whether or not exceptions were included. Iowa frontrunner Sen. Ted Cruz also opposes a rape and incest exception. If either of them gets the nomination, they could well have as difficult a time defending themselves as did Richard Mourdock and Todd Akin.

Universal background checks for gun purchases also would only nibble around the edges of the matter at hand. The president acknowledged as much during last week’s CNN town-hall event. “We’re not going to eliminate gun violence, but we will lessen it,” he said. “And if we take that number from 30,000 down to, let's say, 28,000, that's 2,000 families who don't have to go through what the families at Newtown or San Bernardino or Charleston went through.”

It may take years before winning the fight for universal background checks, so gun control advocates don’t have to worry yet about how ambitious their next steps will be. But they will have to guard against frustration at the slow pace of change.