Planned Parenthood Federation President Cecile Richards testifies before the House Committee on Oversight and Government Reform on Sept. 29. (Gary Cameron/Reuters)

Public opinion will have huge implications for a potential showdown (and shutdown) over Planned Parenthood in December. It will determine just how hard Republicans can press their case to halt federal funding for the women's health-care provider.

But the largely symbolic fight betrays a pretty significant truth about the larger abortion debate. And that is this: Republicans have been winning this battle big-time at the state level — even as opinions about abortion remain pretty stagnant.

Well before congressional lawmakers decided to take a stand this summer to cut about $500 million in annual public funding from Planned Parenthood, more than 30 state legislatures were busy passing a historically high number of measures that would restrict abortion rights. All the while, Americans' opinions on abortion have remained remarkably unchanged — suggesting that this issue, despite the passion involved, isn't necessarily one on which votes are being swung.

From 2011 to 2013, Republican-led state legislatures enacted more restrictions on abortion than in the entire previous decade, according to an analysis from the nonprofit, pro-abortion-rights Guttmacher Institute.

A recap of the abortion restrictions that states such as Arizona, Florida, Kansas and Texas have recently signed into law:

  • requiring mandatory ultrasounds for women considering abortions
  • banning abortion coverage by private health insurers
  • banning abortions after 20 weeks (or sooner) of gestation as well banning providers such as Planned Parenthood from receiving state funding for family planning services
  • implementing restrictions that make it difficult to keep clinics open

Here's how that looks:

Even as these restrictions have been enacted, though, a slight majority of Americans think abortion should be legal in all or most cases, according to five vetted surveys analyzed by The Washington Post's polling team. And even in surveys that find support for greater restrictions, that view has not grown in recent years.

Take surveys from the Pew Research Center, for instance, where 51 percent to 55 percent have said abortion should be legal in all or most cases since 2011. The trendline further back is also fairly stable.

The Planned Parenthood debate, which has been highly visible in political news coverage over the summer and this fall, hasn't greatly shifted Americans' opinions on the topic, either. Across five long-running surveys tracking support for legal abortion, three show slight shifts against abortion rights this fall compared with previous surveys (CBS/NYT, Pew Research, Quinnipiac University), while two show no significant change (CNN/ORC, Public Religion Research Institute). Similar small shifts in abortion attitudes in the past have proven short-lived over the long term.

[Support for Planned Parenthood funding is down, but support for its federal funding is not]

The steady public opinion in the face of heated abortion-restriction debates also suggests that voters simply haven't been swayed by the debates in their state legislatures, a historic majority of which are now held by Republicans, thanks in part to the 2010 midterm elections. It has been a relatively quiet transition on what has otherwise been a very pitched political issue.

Even when some of these abortion-restriction laws have gained national attention — the Supreme Court might look into Texas's 2013 law imposing strict requirements on abortion providers, which shuttered some clinics in the state — we haven't seen a significant voter backlash. Quite the opposite, in fact; Republicans swept even more state legislatures in 2014.

Perhaps abortion just isn't a pressing issue on which votes can change hands. It did rank far down the list for voters in the 2014 election, after all. 

Regardless, though, the public attention paid to and the political capital expended upon a largely symbolic (and unlikely to succeed) fight over Planned Parenthood obscures the fact that Republicans have been winning this fight in very real ways for years.

Scott Clement contributed to this report.