The daily multiple single-issue emails are back.

His face again is becoming a fixture on national television news shows, and he again is a go-to guest for a hot topic.

Sen. Marco Rubio, who generated a loud buzz in 2012 and early 2013 as a strong contender for the 2016 presidential race, took a few steps down from the high stage he occupied during the Senate’s work last year on a bipartisan comprehensive immigration reform bill. After the reform effort stalled in the House, and Tea Party constituents assailed Rubio for backing a measure that allowed a path to citizenship for undocumented immigrants, he stayed in a dimmer spotlight for a few months.

But he’s back swinging, generating talk among political observers about whether he’s back in the ring for a shot at president in 2016.

There are some single-issue immigration voters...he can’t get...back. Rubio is reasserting himself on...foreign policy in anticipation of 2016.

- Erick Erickson, founder, Red State website

The issue the Florida Republican is beating the drum about this time is Venezuela and, secondarily, Russia.

His theme, which he is pushing with a vengeance through several daily mass emails, is that the United States must get tough with the governments of Venezuela and Russia. The Obama administration, he says, cannot be a wimp in the face of mounting aggression by Venezuela’s socialist government against its own people, and by Russia against Ukraine.

Last week emails condemning Venezuelan President Nicolás Maduro’s violent crackdown on protestors demonstrating against him came every day, several times. 

Also last week, he took to the Senate floor and delivered an impassioned 15-minute speech, calling on the United States to wake up to the political unrest “in our own hemisphere,” wrote an op-ed in Politico demanding that Obama get tougher against Russia, and appeared on Sunday morning news shows to press the administration on both Russia and Venezuela. 

The clashes between Venezuelan protestors and the government have claimed at least 18 lives and injured scores.

“I’m not arguing that the U.S. should intervene militarily,” said Rubio in an exchange with constituents that his office emailed to the media on Monday. “I think the President should pronounce himself very clearly that he condemns, in the strongest possible terms, what Nicolás Maduro and their government is doing to the people of Venezuela.”

“Up to now, all we’ve heard is that they are ‘concerned’ about what’s happening in Venezuela,” Rubio said. “They shouldn’t be concerned, they should be outraged, and they should say so. And people all over the world who love peace, love freedom, love liberty, love democracy, and love human rights and respect it, need to know that the U.S. is on their side.”

An Eye On Venezuela And Russia -- And The Other On 2016?

Longtime political and Rubio observers suspect that the senator is leading the pack on calls for a more aggressive U.S. response to Venezuela and Russia with an eye toward 2016.

But many add that Rubio cut his political teeth in a district – South Florida – where foreign policy is as much a key issue among constituents as school budgets, garbage collection and property taxes.

South Florida is home, after all, to the largest Cuban and Venezuelan exile communities in the world, said Otto Reich, former U.S. ambassador to Venezuela from 1986 to 1989, and assistant secretary of state under President George H.W. Bush.

But beyond the local political appeal in Rubio’s home district for tough talk about socialist regimes, Reich said, “When the executive branch does not act, Congress must.”

“Rubio does what a political leader often has to do – find common ground on an important issue,” Reich said of Rubio’s key role in the so-called “Gang of Eight,” the bipartisan group in the Senate that drafted the bill that called for both stricter enforcement of immigration laws and a path to legalization for undocumented immigrants who met a strict set of criteria.

Rubio is also filling a void, Reich said, left by an Obama administration that many Republicans say has been too slow to react to hostile foreign governments.

Rubio and fellow Sen. Bob Menendez, who is a Democrat and also is Cuban-American, recently drafted a resolution urging the United States to impose limited sanctions on Venezuela, such as freezing U.S. assets of -- and denying visas to -- some officials who took part in the violent crackdown on anti-government protesters.

“When the United States is not engaged in the world, trouble normally follows,” said Alex Conant, Rubio's press secretary. "There’s a sense that Washington and especially this administration pay a lot of attention to other parts of the world without looking at what’s in our hemisphere.”

“We’ve proposed resolutions and haven’t heard much of a response from the administration.”

Rubio's Lead On -- Then Retreat From -- Immigration Drew Fire From All Sides

Rubio's very public participation in the Senate bill – he essentially became the face of the effort to gain national support for the bill – ultimately made him a target for all sides.

Rubio got heat from Tea Party members and other conservatives for his embrace for a path to citizenship for undocumented immigrants. Many saw it as a betrayal of conservative values, and questioned whether someone who supported giving what they called amnesty to lawbreakers could truly be a conservative.

A Tea Party group in Rubio’s Florida district held a protest against him last year, and several of his Republican colleagues in Congress singled him out when criticizing the Senate measure.

In Georgia, the head of an anti-illegal immigration group erected a huge billboard in the state urging people to stop “Rubi-Obama Amnesty.”

“There’s the betrayal factor,” said D.A. King, who is head of the goup, and who helped draft several of Georgia’s anti-illegal immigration laws, in an interview with Fox News Latino last year. “It’s a mystery to us why he’s still considered a conservative.”

“In his race for the Senate, Rubio said that he would never support any amnesty,” said King, head of the The Dustin Inman Society, described as a non-partisan coalition of citizens against illegal immigration. “Maybe we need a redefinition of the word conservative, it's more than just not being a Democrat.”

Those who favored more lenient immigration policies initially lauded Rubio for taking a lead role in a reform effort that risked drawing fire from his own party and core constituency. But they soured on him after the effort stalled in the House, and the bill, which the Senate passed, died in Congress last year. 

What vexed this group most was that Rubio virtually disappeared from the immigration reform push, falling conspicuously silent on the issue and seeming to almost avoid it.

“There are some single-issue immigration voters,” said Erick Erickson, founder of the conservative Red State website, to Fox News Latino, “and he can’t get them back. But I don’t know that he ever had them to begin with.”

But Erickson, whose own website opposes a path to legal status for undocumented immigrants and was highly critical of Rubio for his support for it, said the senator can recover from any damage from his performance on immigration and regain credibility with many voters.

“Rubio is reasserting himself on that front, foreign policy, in anticipation of 2016,” Erickson said.

“Not only is this a subject he has really cared about for a long time, he dealt with it when he was in the state legislature in Florida. When it comes to Central and South America turmoil, Florida feels the brunt of it. As a state legislator he had to care about it.”

“Now he has a larger platform,” Erickson said.

Conant said his boss is not taking the foreign policy mantel for self-serving purposes. Rubio has not yet decided, he said, whether he'll run for president.

“First, he’s on the relevant committees – the Senate Intelligence Committee, the Foreign Relations Committee,” said Conant. “Second, Florida and Venezuela have a lot of cultural ties…And third, he feels very strongly that America needs to be engaged in the world.”

Other members of Congress, to be sure, have pushed for a stronger U.S. response to Venezuela and Russia, Erickson said, but Rubio has the star power to get a national spotlight for those who share his view.

D.A. King said he is not ready to dust off the “Tea Party Darling” halo that Rubio wore after his 2010 election to the Senate and crown him with it again.

“Rubio is an all-too-common example of a willing and ambitious politician with no core values happily falling in with the big money D.C. crowd,” King said. “A year ago Rubio was like an intrepid [Sen. Chuck] Schumer-parrot and did seven talk shows on one Sunday peddling another amnesty and a doubling of legal immigration.”

“Now real advocates for American workers and sanity in immigration gleefully watch as he carefully explains that ‘comprehensive immigration reform’ isn't the solution and struggles to evade the issue.”

For his part, Erickson sees Rubio's retreat from the divisive topic of immigration as a smart tactical move.

"He got too overexposed," he said. "He was smart to lie low. Behind the scenes, he's been picking a lot of good fights on the good side" of issues, as far as conservatives go.

And the welcome he received in Alabama last week may be a sign that some conservatives are seeing Rubio's fiery talk about Venezuela and Russia as a redeeming factor. Political donors paid $32,000 for a  meet-and-greet with Rubio, raising about $300,000 for the Senate Republican campaign committee.

"Rubio can't be underestimated," Erickson said.

Elizabeth Llorente can be reached at elizabeth.llorente@foxnewslatino.com

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