(WHTM) – Former President Donald Trump sent shockwaves across Pennsylvania when he formally endorsed Dr. Mehmet Oz in Pennsylvania’s crowded U.S. Senate race.

“I believe that Mehmet Oz will be the one most able to win the General Election against a Radical Left Democrat,” said Trump on Saturday.

Many conservatives have blasted Trump’s decision as ads play across Pennsylvania calling the former television show host Oz a “RHINO” – Republican In Name Only.

“I don’t think the President is getting very good advice,” said Senate candidate Carla Sands, who served as Trump’s Danish ambassador.

“If you don’t want to send a RINO to represent us, I hope you’ll choose me, I’ll never let you down.”

Lowman Henry of the PA Leadership Conference says Trump’s decision to endorse Oz has left many scratching their heads.

“A lot of the Trump diehards saying, Ok, this is Trump’s guy this is who we’re gonna vote for,” said Henry, “and some people scratching their heads, ‘why did Donald Trump choose to endorse him and at this time?'”

Danielle Gross of Shelly-Lyons Communications says many Republicans do see Oz as a liberal, but to people who actually liberal, “I can assure you, he does not seem to be one.”

Oz previously served as a member of the President’s Council on Sports, Nutrition and Fitness and has run campaign ads featuring Trump’s appearance on The Dr. Oz Show.

“I am honored to receive President Trump’s full support and endorsement, and I thank him for that,” said Oz. “President Trump knows how critical it is to change the kinds of people we send to Washington. I’m ready to bring an America First agenda to the Senate for Pennsylvania.”

In a recent WHTM/Emerson College Polling/The Hill poll of 1,000 likely Republican Pennsylvania voters, McCormick finished first in the Senate race with 17.8%, followed by Oz with 16.6%. Nearly 33% of voters said they were undecided in the Republican Senate race.

Seven candidates are currently in the Republican primary race, including Trump’s former Danish ambassador Carla Sands, Fox News contributor Kathy Barnette, and former Lt. Governor candidate Jef Bartos.

McCormick interviewed with Trump in 2016 for a possible position in his administration and has been endorsed by Parnell and former Trump Secretary of State Mike Pompeo.

Sands responded to the endorsement on Saturday night, tweeting in part, “Pennsylvania can’t risk sending another weak-kneed RINO to Washington DC to represent us.”

In a WHTM/Emerson College Polling/The Hill poll released in March, 61% of Pennsylvania Republican voters said they would vote for a Trump-endorsed candidate.

More than 25% said an endorsement would make no difference and 13.2% said it would make them less likely to support a candidate.

A criticism brought against Oz by campaign opponents has been his residency, with people questioning whether he’s from Pennsylvania.

“If that’s the biggest criticism against me, I’m in good shape,” Oz told abc27’s Dennis Owens during a March campaign visit to a Harrisburg diner.

The 61-year-old former cardiothoracic surgeon highlighted how he went to medical school at the University of Pennsylvania School of Medicine and earned a business degree from the Wharton School of the University of Pennsylvania.

“I’m very proud that I’m a Pennsylvanian,” said Oz. “They care much more for what I stand for than where I’m from.”

Oz recently submitted a public financial disclosure report that includes over $100 million worth of assets and properties in at least four states. The 61-year-old also holds dual citizenship with Turkey but has vowed to renounce it should he be elected to the Senate. If elected, Oz would be the first Muslim U.S. Senator and likely the wealthiest.

Trump has not yet endorsed a candidate in the race for Governor in Pennsylvania.

Pennsylvania’s primary election will be held on May 17.