In a new op-ed, Senator and GOP presidential candidate Marco Rubio laid into Barack Obama’s policies regarding Iran:

Iran has already stretched the terms of Obama’s deal. Iran is now trying to claim that a U.S. law aimed at protecting Americans from terrorists trying to come to the United States is an American violation of the agreement. This is a blatant attempt to pressure the Obama administration not to seek or enforce any new sanctions whatsoever, even those targeting human-rights abuses and support for terrorism, which are allowed under the deal. It has twice tested ballistic missiles — violating a U.N. Security Council resolution. On December 31 the supposed moderate Iranian president Hassan Rouhani even stated that Iran would be expanding its ballistic missile program. This comes just weeks after the Obama administration joined with its diplomatic partners to sweep Iran’s past illicit nuclear-weapons activities under the rug.

The administration’s reversal of position on this key issue set a terrible precedent for the nuclear agreement. The United States has willingly conceded the crucial baseline it needs to guard against any future move toward Iranian weaponization. America’s enemies will also take heart: They now have a model for obfuscating their illicit activities with no repercussions.

President Obama’s rollover on Iran’s past attempts to create a nuclear weapon is part of a disturbing pattern. The White House is reportedly delaying planned sanctions against Iran’s ballistic-missile program; has done nothing to punish Suleimani’s illegal travel to Russia; failed to secure the release of imprisoned Americans; and remained quiet about Iran’s flagrant human-rights violations and its aggressive actions in the region. The deal hasn’t even been implemented yet, and it’s gone from relieving nuclear-weapons-related sanctions, to becoming a get-out-of-jail-free card for whatever violations of international norms and laws Tehran cares to undertake.

Rubio is almost certainly the Republican with the most “muscular” foreign policy, and would represent a pretty drastic change from the failures of the Obama era. Are voters willing to change that much?