'No Trump questions': GOP senator shuts down debate on his party's presidential nominee

Sen. Todd Young (R-IN) will not be talking about his own party's presumptive nominee to the presidency.

Per NBC News' Frank Thorp, Young was asked by reporters whether he'd be attending a planned meeting between former President Donald Trump and Senate Republicans on Thursday.

"No Trump questions," Young replied.

A reporter then asked him if this meant that they weren't allowed to ask him about Trump ever or for just a limited time.

"Until I decide to make it no longer a rule," Young said.

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Young is one of the few Republican senators who has yet to endorse Trump's presidential campaign.

When asked about his reluctance to back Trump last year, Young indicated multiple reasons but settled on his frequent praise of Russian President Vladimir Putin as one particularly troubling aspect of the former president.

"I think President Trump's judgment is wrong in this case," he said. "President Putin and his government have engaged in war crimes."

Young is just one of many big-name Republicans who have not yet backed Trump this year. Others include retiring Sen. Mitt Romney (R-UT), former Rep. Liz Cheney (R-WY), former House Speaker Paul Ryan (R-WI), and former Vice President Mike Pence.

Those four have made it clear they don't intend to give him their endorsement.

Additionally, several members of Trump's own administration have said they will not support his candidacy, including former Defense Secretary Mark Esper, former national security adviser John Bolton, and former White House communications director Anthony Scaramucci.