“There can’t be an America without the American Dream … and that is what’s being undermined by ObamaCare,” Rubio said on the Senate floor Tuesday. “If your dream is to open your own business and grow it, then ObamaCare is hurting you.”

Cruz and Rubio are spending the evening speaking out against Democratic efforts to advance a resolution to fund the government.

Senate Majority Leader Harry ReidHarry Mason ReidAmendments fuel resentments within Senate GOP Donald Trump is delivering on his promises and voters are noticing Danny Tarkanian wins Nevada GOP congressional primary MORE (D-Nev.) is expected to advance H.J.Res. 59 with an amendment removing House language that defunds ObamaCare. A vote to end debate on the motion to proceed is expected Wednesday even if Cruz continues to speak on the Senate floor.

The government will shut down on Oct. 1 if Congress doesn't approve some form of government funding measure. 

Cruz has been pushing Republican colleagues to obstruct the spending bill as a way to generate leverage to end the healthcare law. Rubio joined Cruz after he had been on the floor for more than four hours.

Rubio said ObamaCare is harming the economy and causing businesses to reduce worker hours. The law includes an employer mandate that require businesses with more than 50 full-time employees to provide health insurance to employees.

“The very people they said this plan, this bill, would help are the very people its hurting the most,” Rubio said.

Democrats point out that the law is already benefiting those with preexisting conditions who can’t be denied coverage, people younger than 26 who can stay on a parent’s insurance plan and women who now pay less for preventive healthcare.

Both Rubio and Cruz are considered potential GOP presidential nominees in 2016.