Washington (CNN) - Call it a very early look at what could possibly happen in November 2016.
According to a new national poll, Hillary Clinton would top New Jersey Gov. Chris Christie and Sen. Rand Paul of Kentucky in hypothetical presidential election showdowns.
But a Quinnipiac University survey indicates that Christie would top Vice President Joe Biden, with Biden and Paul dead even, in possible matchups.
According to the survey, 46% of registered voters would back the former secretary of state if she were the Democratic presidential nominee, with 40% supporting Christie if he were the GOP nominee. Clinton's six-point margin is down slightly from an eight-point advantage in a Quinnipiac poll conducted in May.
Clinton tops Paul 50%-38%, with her 12-point lead up from an eight-point advantage in May.
The former first lady, senator from New York and 2008 Democratic presidential candidate has a 55%-38% favorable/unfavorable rating, with Christie standing at 45%-18%, including a 41%-19% favorable rating among Democrats.
"Former Secretary of State Hillary Clinton remains the front-runner for 2016 if she chooses to run," says Peter A. Brown, assistant director of the Quinnipiac University Polling Institute. "But New Jersey Gov. Christopher Christie's favorability numbers are impressive and if he can win over a solid share of those who do not yet have an opinion about him, he could be a very formidable candidate in 2016. Candidates with more than 2-1 favorability ratios don't grow on trees."
According to the poll, Christie leads Biden 46%-35%, up from a 43%-40% margin in May. And Biden and Paul are deadlocked at 42%. Paul had a four-point margin over the vice president in May.
Thirty-eight percent of those questioned said they had a favorable rating of Biden, with 44% saying they see him in an unfavorable light. According to the survey, Paul stands at 31%-28%, favorable/unfavorable.
Clinton, Biden, Christie and Paul are all considered possible contenders in the 2016 race for the White House.
The Quinnipiac University survey was conducted June 28-July 8, with 2,014 registered voters nationwide questioned by telephone. The survey's overall sampling error is plus or minus 2.2 percentage points.
- CNN Political Editor Paul Steinhauser contributed to this report.