A new ad characterizes Rubio as the key opponent of "Obama’s bad Iran nuclear deal."
Rep. Chris Van Hollen spoke out after the Supreme Court's Affordable Care Act ruling.
The presidential candidate suggests his legislation is the latest step against wealth inequality.
Trump said the network was caving in to pressure from the Mexican government.
The New Jersey governor would be the 14th Republican to enter the race for the GOP nomination.
GOP presidential hopefuls attacked the decision upholding a key ObamaCare provision.
"Bernie Sanders is no progressive when it comes to guns,” the ad says.
Rep. Jeff Miller (R-Fla.) disputed a report that he has already made up his mind.
"I very rarely read in any coverage of Bernie that he is a socialist,” she said.
Sanders said hunters and shooting enthusiasts "should not be condemned."