Updated

Every day this week, several times each day, emails hit inboxes from the office of U.S. Sen. Marco Rubio on the immigration reform bill he has been instrumental in drafting.

In the last two days alone, the senator’s office sent out about a dozen lengthy emails, some of them titled “Myths vs. Fact,” addressing virtually every criticism that the bill’s opponents – including his conservative colleagues – have raised. He spent last weekend stomping for the bill on Sunday news shows.

And this week, he has personally pitched it to fellow congressional members, conservative talk show hosts, and stakeholders in the immigration debate. When some of his colleagues in Congress urged rethinking the reform bill after the Boston bombing when reports said the suspects were foreign-born, Rubio assailed them, calling the link irresponsible.

Rubio also created a website on the immigration bill that he said is “one-stop shop for helping the public separate fact from fiction as this debate continues.”

The Florida Republican is part of the bipartisan “Gang of Eight,” four Republicans and four Democrats in the Senate who put together the nearly 900-page bill, which would tighten border security, provide a pathway to legalization for undocumented immigrants under strict criteria, and revamp the guest worker program, among other things.

Indeed, Rubio, who has much riding on the bill’s success – his conservative bonafides, his stature within his party, bruised by last year’s poor showing in the presidential election, and his own presidential prospects for 2016 – is firing on all cylinders to help push the measure through the finish line.

Rubio’s spokesman, Alex Burgos, said the senator is determined to counter the hysterics and misinformation about the bill with facts and perspective.

“Because our immigration system is broken in so many ways and requires many reforms to fix it, it will always be far easier to attack proposed solutions than to offer them,” Burgos told Fox News Latino. “It’s why a lot of misinformation tends to land in people’s inboxes and gets regurgitated in the media. It’s important to clear up misconceptions about this bill as it continues to be debated, because the American people deserve an immigration debate based on facts.”

That is not to say, Burgos stressed, that the senator is trying to silence or shut out those who object to parts of the measure. The senator is trying to keep the attention on the bill constructive, he said.

“No one is saying the bill is perfect, which is why Senator Rubio welcomes public input on ways to improve it,” Burgos said. “Peddling myths about it simply isn’t a constructive way to engage in this debate.”

Those who favor strict immigration laws, and who are loathe to consider any break for undocumented immigrants, vehemently oppose the part that would give an undetermined number of the 11 million people not legally here a chance to legalize their status. They say it is tantamount to rewarding lawbreakers, and creates more competition for jobs at a time when many Americans are unemployed.

Some political leaders and members of some conservative groups who held hard-line views of immigration have softened their stance, now saying they’ll support a path to legalization so long as the border is first secured, and people who have been waiting to come to the United States legally are not penalized for having done so. They say the 11 million people here illegally are not going to return to their countries, and that the United States cannot realistically track them all down and deport them.

The support by Rubio and other conservative Republicans for giving undocumented immigrants a chance to legalize without leaving the United States has been key in influencing others to support it as well.

But those who oppose legalization call it an “amnesty” and remain steadfast in their views. They are a concern for the senator and others who want an immigration reform bill passed this year.

Advocates of more lenient immigration policies laud Rubio’s public relations push for the measure, even though they say they disagree with some parts of it.

“It’s spectacular, I’ve never seen such vigorous defense of immigration reform from such a prominent Republican,” said Laura W. Murphy, the director of the American Civil Liberties Union’s Washington D.C. legislative office. “It’s one thing to push legislation out there and say you’re for it, it’s another thing to go the extra mile to dispel myths about immigration in the United States.”

Murphy said it shows the effort is bipartisan – and being taken seriously.

“It will make a difference, Rubio is considered a presidential contender,” Murphy said. “He’s creating a safe space for a discussion that can take place in thoughtful ways, as opposed to only being about demagoguery from one side or the other.”

Groups that favor strict immigration laws find Rubio’s push this week irritating.

“Obviously he’s feeling the pressure, or he wouldn’t be churning out these emails every hour on the hour if he wasn’t,” said Ira Mehlman, spokesman for the Federation for American Immigration Reform, or FAIR, a Washington D.C.-based group that favors strict immigration policies."

“Mr. Rubio can call it anything he wants, but it’s an outright amnesty. Anything people did – like identity theft – in the furtherance of breaking immigration laws will be forgiven if they pay fines, show they’ve paid taxes. That’s amnesty, no one will be prosecuted.”

It is such criticism that Rubio’s emails attempt to take apart. Rubio insisted the proposal does not include an "amnesty" provision that fellow conservatives have called a deal-breaker.

"We're not awarding anybody anything,” Rubio said. “All we're doing is giving people the opportunity to eventually earn access to our new, improved and modernized legal immigration system."

When talk show host Rush Limbaugh this week asked Rubio why he was devoting so much attention to immigration, he said: “If it was up to me, if I controlled the flow of business in the Senate we would be focused on tax reform and how to get our economy growing again and how to get the debt under control."

"But the reality is the Democrats are going to raise the issue of immigration. So if they're going to raise this issue and force us to address it, then we have to have an alternative.”