Even as he runs evenly with Barack Obama in national polls, Mitt Romney -- the newly official Republican presidential nominee -- continues to trail the president in one regard: basic popularity.

In a new Washington Post-ABC News poll, 40 percent of voters say they have favorable impressions of Romney, with 50 percent saying so about Obama. And among all adults, Romney’s popularity has dipped since earlier in the month, to 35 percent, with a record high (albeit by a single point) 51 percent holding unfavorable opinions.

At 50 percent, among both all adults and registered voters, the president is not in clearly positive territory either, and is far less popular than he was when he ran for office four years ago. The 50-percent-mark among all Americans is a low-point for the year for the president, who was in the 60s for most of fall 2008.

Political independents are about evenly split on Obama, with 44 percent holding favorable views, 48 percent unfavorable ones. They are clearly negative on Romney, 31 positive, 51 negative. In the Washington Post-ABC News poll released Monday, independent voters divided their votes between the two contenders.

One negative for Romney as the GOP convention enters its second full day, is that among all self-identified Republicans his favorability has dropped nine percentage points to a still high 74 percent. Things are a bit brighter on the other side: 86 percent of Democrats have favorable views of Obama.