President Obama flies home Saturday afternoon after a three-day trip to Mexico and Costa Rica that focused on economic trade and security  and touched on immigration. But in several appearances and news conferences, we learned about Obama’s thinking on a few critical issues in the United States.

President Obama

1. Obama thinks sexually active 15-year-old girls should be able to buy emergency contraception without consulting an adult.

 The Food and Drug Administration last week approved over-the-counter distribution of the morning-after pill, also known as Plan B, for women ages 15 and over. At the same time, the Justice Department appealed a federal court ruling requiring that Plan B be made available to girls and women of all ages.

The court order came after a decision in December 2011 by Health and Human Services Secretary Kathleen Sebelius to overrule FDA scientists, who had concluded that the pill was safe to distribute over the counter to women and girls of all ages.

At the time, invoking his own daughters, Obama said he supported Sebelius’s decision.

Asked about the new FDA action at a news conference in Mexico City, Obama said he was fine with it.

“The first time around, where there were no age restrictions, Secretary Sebelius expressed concerns and I supported those concerns,” Obama said, adding that now “I’m very comfortable with the decision they’ve made right now based on solid scientific evidence for girls 15 and older.”

2. He feels impassioned about trying again on guns.

Obama chimed in when Mexican President Enrique Peña Nieto was asked about U.S. gun policy, insisting that he will try again to tighten gun laws despite the Senate’s rejection of a fairly modest background-checks bill last month.

“What I’m most moved by are the victims of gun violence, not just in Mexico, but back home -- like the parents in Newtown,” Obama said. The failure of the Senate bill “was not the end; this was the beginning.”

Obama noted it took six to eight tries the last time gun legislation passed in Washington. “Things happen somewhat slowly in Washington, but this is just the first round, he said. “One thing I am is persistent.”

The remarks recalled Obama’s first trip to Mexico four years ago, when he was asked about whether he would try to reinstate a ban on assault weapons.

He replied that he supported such a ban, but it would be difficult.

“I have not backed off at all from my belief that the gun -- the assault weapons ban -- made sense,” Obama said then. “Having said that, I think none of us are under any illusion that reinstating that ban would be easy. And so, what we've focused on is how we can improve our enforcement of existing laws, because even under current law, trafficking illegal firearms, sending them across a border, is illegal. That's something that we can stop.”

3. Obama will sign any immigration bill that fits the basic criteria he has laid out, even if it falls far short of meeting all the provisions he supports, including one assuring gays and lesbian of equal treatment.

Obama said in Mexico that the current bill is a good start, even if it “doesn’t contain everything I want, and I suspect that the final legislation will not contain everything I want.  It won't contain everything that Republican leaders want, either.”

But he added that if it meets all his basic thresholds, “that's the core of what we need.” His basic criteria include enhanced border security, a crack down on employers who do not follow immigration law, a streamlining of the legal immigration system and a pathway to citizenship for the 11 million illegal immigrants in the country.

In Costa Rica the next day, Obama said he supports a provision that would grant LGBT couples the same immigration rights as straight couples. But he made clear it is not a make-or-break requirement.

“I’ve said in the past that the LGBT community should be treated like everybody else.  That's, to me, the essential, core principle behind our founding documents,” Obama said.

However, he added, “as is true with every bill, if there are things that end up being left out in this bill, … then we go back at it and we fix what’s not there.”

4. Obama wants international support for any significant escalation of the U.S. role in Syria and sees virtually no way that would include the involvement of U.S. ground troops.

In Costa Rica, Obama went out of his way to make this point after neglecting to answer a question about the potential use of ground troops. The United States is now considering a range of options to help the Syrian opposition after evidence emerged that chemical weapons were used in Syria, though officials have cautioned the evidence is still being assessed.

Obama said that if officials determine that chemical weapons were used in a systematic way in Syria, “we will present that to the international community, because I think this is, again, not just an American problem; this is a world problem.”

Asked about ground troops, he said that generally he doesn’t “rule things out as commander-in-chief because circumstances change and you want to make sure that I always have the full power of the United States at our disposal.”

But he said he does “not foresee a scenario in which boots on the ground in Syria, American boots on the ground in Syria, would not only be good for America, but also would be good for Syria.” He said he hears the same from leaders in the region who want to see an end to the regime of Bashar al-Assad.

5. Obama isn’t optimistic that the big new policy idea of his second term -- free early-childhood education for all 4-year-olds from poor and moderate income families -- will make it through Congress.

Obama has proposed increasing cigarette taxes to pay for the expansion, which would cost nearly $80 billion over 10 years, but didn’t evince much confidence it would happen when asked about the idea at a forum in Costa Rice.

“Whether we’re going to be able to get that passed or not, I don’t know,” he told said. ”It’s always a struggle to get new revenues for new endeavors.”

But he said he was confident of the value of the idea.

“There’s no bigger bang for the buck than making this investment in early-childhood education,” the president said.