(Matt Rourke/AP Photo)

If 2016 brings another Bush-Clinton matchup, not all famous last names are equal at the start.

The latest ABC News/Washington Post poll makes clear why it's better to be associated with the 42nd president than the 43rd and 41st, at least for now.

The poll has plenty of good news for Hillary Rodham Clinton. Two-thirds of Americans say they'd consider voting for Clinton in 2016, and a full 25 percent say they will definitely support her. Again, among all Americans - not just Democrats, or Democrats and independents - one in four say they are fully on board for Hillary Clinton right now, no questions asked.

As for Jeb Bush? He has the rock-solid support of just 6 percent, a level that puts him alongside Mike Huckabee and Gov. Chris Christie. He ranks below Sen. Rand Paul, and even Mitt Romney.

What's worse for him, nearly half of Americans - 48 percent in the poll - say they will definitely not support the former Florida governor for president. The only other person who matches that rule-out rate in the poll is Romney, whom Americans, of course, rather recently went on record not supporting. He is highly unlikely to run again in any event.

Clinton's definitely-not-support number is 32 percent - lower than it was at the start of the 2008 cycle, when she lost the Democratic primaries to President Obama. That suggests that the Clinton brand is getting stronger, while the Bush brand is staying weak.

The poll, as with any 2016 check-in taken during 2014, shows little firm opinion on some candidates who are likely to become major players, including Gov. Scott Walker and Sen. Ted Cruz. All candidates - even those with famous political names - have plenty of time to turn around opinions about themselves, and anti-Bush sentiments have softened over time.

But with the biggest gathering of possible Republican presidential contenders of the year going on this week in Washington, at the Conservative Political Action Conference, it's interesting to note that Jeb Bush isn't in attendance. The Bush legacy, though, is hard to miss, every time conservatives rail against runaway government spending and perpetual deficits.

As for Jeb himself, he's taking friendly fire for his strong support of Common Core education standards. According to the CPAC schedule, there's a panel discussion this afternoon that will "Frame the debate between well intentioned education conservatives who WANT higher school performance and the realists who understand that once the feds are involved, all is lost."

It's too early to suggest all is lost for any potential candidate. But with focus falling on Christie's need to build himself back up, recall that he is far from the only presidential contender with plenty of work to do.