Rubio remotely blocks Mexico ambassador nominee while campaigning
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Sen. Marco RubioMarco Antonio RubioRubio: McCabe 'should've been allowed to finish through the weekend' For Tillerson, bucking Trump became a job-killer At least six dead after pedestrian bridge collapses on cars in Florida MORE (R-Fla.) on Thursday remotely blocked the Senate from confirming President Obama's ambassador to Mexico, even though he is campaigning in South Carolina.

Sen. Tom UdallThomas (Tom) Stewart UdallOvernight Energy: Dem says EPA isn't cooperating on 'privacy booth' probe | Tribe, Zinke split over border wall | Greens tout support for renewables in swing states Overnight Regulation: Facebook faces new crisis over Cambridge Analytica data | Whistleblower gets record SEC payout | Self-driving Uber car kills pedestrian | Trump bans trading in Venezuelan cryptocurrency Senate Dem: Pruitt isn’t cooperating with ‘privacy booth’ probe MORE (D-N.M.) tried to get unanimous consent to confirm Roberta Jacobson, who was nominated in June. Sen. Mike LeeMichael (Mike) Shumway LeeSenate tees up Yemen vote for Tuesday Congress moving to end US involvement in Yemen This week: Congress races to prevent third shutdown MORE (R-Utah) objected, noting that he was doing so on behalf of Rubio, a GOP presidential candidate.

Jacobson, who is currently the State Department's assistant secretary for Western Hemisphere affairs, has drawn flack from Republicans and some Democrats over her role in leading the Obama administration's negotiations with Cuba to restore relations. 
Rubio has repeatedly criticized the president's handling of the island country, suggesting Obama is relaxing decades-old travel and trade rules without requiring political or human rights reforms in return. 
He also wrote a letter to Jacobson last month about reports that a Hellfire missile was sent to Cuba after being used during a European training exercise. 
"The fact that the administration, including you, have apparently tried to withhold this information from the congressional debate and public discussion over U.S.-Cuba policy is disgraceful," he said at the time. 
A State Department official said Congress was briefed on the issue in February 2015.
Udall, separately, defended Jacobson, calling her a "highly qualified career nominee." 
"She's ready to serve. She has solid support on both sides of the aisle," he said.