Former Secretary of State Hillary Clinton ended a self-imposed political hiatus on Monday, slamming Republican-backed voter ID laws in a biting speech in San Francisco.

Clinton said the Supreme Court in June had done serious damage with its landmark Voting Rights Act ruling, which cleared the way for states with a history of discrimination to tighten voting laws without federal approval. She also denounced voter ID laws pushed through by state legislatures controlled by the GOP, saying they were being justified as tools to fight the "phantom epidemic of voter fraud," but really just made it harder for minorities and the poor to exercise their voting rights. She referred to North Carolina's new election rules, which were signed into law by Republican Gov. Pat McCrory this week, as the "greatest hits of voter suppression."

"Not every obstacle is related to race, but anyone who says that racial discrimination is no longer a problem in American elections must not be paying attention," Clinton said.

Of course, this is hardly the first speech Clinton has given since she left the Obama administration. However, this address featured an overtly partisan tone on a hot-button issue, prompting analysts to brand her remarks as the strongest evidence to date that Clinton is preparing to launch another bid for the presidency in 2016.

The question is: Why did she choose this issue?

Analysts say that Clinton has the Democratic Party's centrists in her pocket, and that her sharp words on voting rights will appeal to a progressive base that has long been wary of the Clintons, helping insulate her against a challenge from the left.

And while she is a clear front-runner at this early stage, she needs to step into the spotlight now and again to remind voters of her presence. Sean Sullivan at The Washington Post says Clinton "can afford to keep a low public profile more than the other potential 2016ers. But she simply can't be a non-factor on the big issues of the day."

Voting rights, Sullivan says, is an ideal place for Clinton to start. It will get her into the game on an issue that has galvanized activists in many states, including election battlegrounds such as North Carolina and Florida. "It's also a topic over which Clinton could begin to make her case as the heir apparent to Obama and try to persuade parts of his coalition — minorities and liberals in particular — to back her," Sullivan adds.

Expect more from Clinton in the coming weeks, particularly on the subjects of homeland security and foreign policy. Here's Traci G. Lee at MSNBC on Clinton's upcoming schedule:

Clinton, who is seen as the frontrunner for the 2016 Democratic presidential nomination, said she plans to speak in September about the "balance and transparency necessary in our national security policies," then later in the fall "will address implications on these issues for [America’s] global leadership and moral standing around the world." [MSNBC]

The Obama administration has been heavily criticized by liberals for the National Security Agency's broad surveillance program, which means Clinton has another opportunity here to shore up support on the left — or toe the centrist line.

As for the U.S.'s "moral standing" in the world, Obama has been pilloried by conservatives for taking what could be called a relativist approach to foreign policy, in stark opposition to George W. Bush's more Manichaean view of world affairs. Again: Another opportunity for Clinton to position herself on a big issue in a potential run-up to 2016. Should be an interesting September in the world of Democratic politics.