Mr. Youngkin, a wealthy newcomer to politics who walked a line between the Trump base of the G.O.P. and business interests, will look to test Democrats’ strength in the blue-leaning state in November.

Mr. Youngkin, a wealthy newcomer to politics who walked a line between the Trump base of the G.O.P. and business interests, will look to test Democrats’ strength in the blue-leaning state in November.