Donald Trump holds a 3% lead over President Joe Biden in a national poll average, with one survey showing the former president has gained five points over his Democratic rival since the beginning of July. A CBS News/YouGov poll taken between July 16 and July 18, the day Trump accepted the Republican nomination for president at the Republican National Convention, found that the former president has extended his advantage over Biden by five points: 52% to 47% since July 3 when a survey had Trump up 50% to 48%. The RealClearPolitics’ average of the polls shows Trump sitting atop a 3-point lead, w…