The bill is expected to pass at some point this week, but the majority of Republicans in the Senate oppose the bill even with proposed measures to increase security at U.S. borders.
"They oppose the bill because they have heard that it creates a taxpayer subsidy for people 'to buy a car or a scooter,'" he said. "That is not true. Nothing in this bill allows that."
Critics have also said that the Florida senator is only pushing immigration reform to further his career and possibly run for president.
"This most certainly isn’t about gaining support for future office," he said. "Many conservative commentators and leaders who I deeply respect, and who I agree with on practically every other issue, are disappointed about my involvement in this debate."