Democratic presidential front-runner Hillary Clinton rebuked Senate Republicans on Monday for denying a hearing to U.S. Supreme Court nominee Merrick Garland, accusing them of obstructionism, and warned of dangers if Donald Trump appointed the next justice.

In a speech in Wisconsin, Clinton put the future of the Supreme Court at the center of the election debate, cautioning that any Trump-appointed justices would be likely to roll back workers' and abortion rights and "demolish pillars of the progressive movement."

"What kind of justice would a President Trump appoint, or for that matter what kind of attorney general?" she asked, noting the Republican front-runner wants a temporary ban on Muslims entering the country and the deportation of millions of undocumented immigrants.