Ronald Reagan, the 40th President (1981-1989), was the most conservative President of the 20th century, who most Republicans have modeled themselves on, regarding his beliefs and record in office.
But today, most Republicans are subservient to Donald Trump, the 45th (2017-2021) and 47th (2025- ) President, and it is very clear that the two men have very little in common, despite both technically being Republican Presidents.
Reagan, for all of his faults, and the criticisms that have been made of his record in office, and his beliefs, was diametrically opposite from Trump on two key issues that now dominate the Trump Presidency.
Reagan made clear his opposition to high protective tariffs, while Trump is promoting a national and world wide crisis with his “Tariff Wars” against all nations, with many nations being assessed a totally insane level of tariffs on their goods.
Reagan also signed immigration reform in 1986, legitimizing many undocumented immigrants, perceving their positive contributions to the American economy and society, while Trump is determined to deport, if he is successful in doing so, ten or more millions of immigrants, despite the dire need for their labor, and the contributions most of them have made to the nation!
Republican Presidential candidates since Reagan, including the two Bush Presidents, but also John McCain and Mitt Romney, supported further immigration reform, as did some Republicans in Congress, but now most Republicans remain silent as Trump declares war on immigration.
So it seems quite obvious that if Ronald Reagan were alive today, he would be a vehement opponent of Donald Trump!