President Joe Biden and Donald Trump both inched closer to their respective party conventions on Tuesday after sweeping their primaries in the five states of Ohio, Florida, Illinois, Kansas and Arizona.

       The final call, in Arizona, was made in favour of the two men shortly after 8pm local time by the Associated Press.

       But all eyes were on the Republican Senate race in Ohio, which placed Mr Trump’s endorsement power under fresh scrutiny.

       The presidential candidate’s MAGA representative in the race, former car salesman Bernie Moreno, overcame a pair of GOP establishment rivals, state senator Matt Dolan and secretary of state Frank LaRose, setting him to challenge Democrat Sherrod Brown.

       The AP called the race in the Buckeye State for Mr Moreno shortly after 8.35pm local time.

       The Republican presidential nominee had hailed his pick as a “fantastic guy” during a 90-minute address at the Dayton Air Show on Saturday and laid into Mr Dolan, whom he labelled a “RINO” (Republican in Name Only) and “the next Mitt Romney”.