Eagle Forum doubled down Monday on a 15-page critique its founder Phyllis Schlafy dropped on Sen. Marco Rubio last week, calling his record on immigration policy highly inconsistent.

"The real Marco Rubio on immigration is a someone that Marco Rubio the presidential contender doesn't want early-state voters to see," Eagle Forum President Ed Martin wrote in a statement. "He ran for the Senate in 2010 as a young, energetic, anti-amnesty conservative, earning the confidence of Phyllis and so many other leaders. Once in office, he became a leading co-sponsor on Chuck Schumer's 'Gang of 8' amnesty bill. Now he's trying to explain it all away in presidential debates."

The conservative interest group has launched an official campaign against Rubio's presidential bid. The timing for the attack could not be more critical. Martin told the Washington Examiner the organization is focused on airing Rubio's policy flip-flop to primary state voters, especially those in New Hampshire, where the latest polling has Rubio in second place just hours before Republicans take to the polls.

Schlafly, a constitutional lawyer who has written about immigration law for two decades, was not always a critic of Rubio. In 2009, when then-State House Speaker Rubio launched his campaign for a vacated U.S. Senate seat, his odds of beating former GOP Gov. Charlie Crist were bleak. Enter Schlafly. A state leader had told her Rubio was a true conservative and encouraged her to invest in the single-digit candidate, Martin told the Examiner. Her financial support, endorsement and advice helped Rubio win the party's nomination and election.

"We don't do that without a sense of who we're doing it for," Martin said.

Phyllis Schlafly and Marco Rubio in 2009 at a Florida senatorial fundraiser (Eagle Forum)

Eagle Forum said Rubio had been explicit to Schlafly and Floridians about going to fight the "establishment" GOP in Washington on immigration specifically, but in 2012 that position changed when he led an effort to pass comprehensive immigration reform with the Gang of Eight bill.

"That's a pretty dramatic shift of when he came into office," Martin added.

Rubio has been attacked by others on his immigration records during Republican debates. Immigration, which in recent national elections has not been an issue that drove voters to the polls, gained significant traction early in this year's election cycle.

GOP front-runner Donald Trump insists he made immigration a top issue since he launched his campaign last June. Eagle Forum agrees he was right to credit himself.

"A year ago if you told us we would have a full-throated conversation on immigration, I don't know if you would've believed it. It's attributable to his [Trump's] entry," Martin said.

Trump has continued to call for the enforcement and reform of immigration policies, causing voters to scrutinize other candidates' positions.

The conservative group applauded Donald Trump and Sen. Ted Cruz for their immigration records, but said Rubio will have to prove his new swing to the right is genuine.

Cruz is ranked first in the Examiner's presidential latest power rankings, followed by Rubio and Trump, respectively.