AdvertisementWASHINGTON --On a day meant for unity and celebration, President Donald Trump vowed to "safeguard our values" from enemies within -- leftists, looters, agitators, he said -- in a Fourth of July speech packed with all the grievances and combativeness of his political rallies.Trump watched paratroopers float to the ground in a tribute to America, greeted his audience of front-line medical workers and others central in responding to the coronavirus pandemic, and opened up on those who "slander" him and disrespect the country's past."We are now in the process of defeating the...…AdvertisementWASHINGTON --On a day meant for unity and celebration, President Donald Trump vowed to "safeguard our values" from enemies within -- leftists, looters, agitators, he said -- in a Fourth of July speech packed with all the grievances and combativeness of his political rallies.Trump watched paratroopers float to the ground in a tribute to America, greeted his audience of front-line medical workers and others central in responding to the coronavirus pandemic, and opened up on those who "slander" him and disrespect the country's past."We are now in the process of defeating the...WW…