Washington (CNN) - She's still the overwhelming front runner in the race for the 2016 Democratic presidential nomination, but according to a new national poll Hillary Clinton's support has slightly deteriorated since the beginning of the year.
And a CNN/ORC International survey released Tuesday morning also indicates that while the hunt for the Republican nomination remains wide open at this very early point, former Florida Gov. Jeb Bush is now tied with Sen. Rand Paul of Kentucky at the top of a crowded list of potential contenders.
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According to the poll, 64% of Democrats and independents who lean towards the party say they most likely would support the former secretary of state for the nomination if Clinton decides to make a second run for the White House. That's down six-percentage points from January, when seven in ten said they'd back Clinton. Nineteen percent say they are likely to support a Democratic presidential candidate who's more conservative than Clinton, up four points from January, with 13% saying they'd back a candidate more liberal than Clinton, up three points from the beginning of the year.
"Clinton is still in a commanding position, but the poll suggests that some rank and file Democrats are shopping for an alternative but have not found one yet in the list of potential candidates offered to them in other polls," says CNN Polling Director Keating Holland.
Clinton has said she'll decide by the end of the year whether she'll launch another bid for the presidency. Until then, Clinton, who stepped down as America's top diplomat early last year, constantly remains in the media spotlight.
"She has been in the news non-stop and so people are seeing her more and more as a politician and less as secretary of state, so that appears to have cost her a bit," says CNN Chief National Correspondent John King.
"Enough to broaden the field of potential challengers? Highly doubtful, but if she drops more as the year goes on it might start more of a conversation in the party," King adds.
Free-for-all for GOP nomination
A familiar name is also at the top of the GOP list. Thirteen percent of Republicans and independents who lean towards the GOP say they are likely to support Bush, who stood at 9% support in CNN's last poll, which was conducted in early March. Bush is tied with Paul, who edged down three points from March.
One point back is Rep. Paul Ryan of Wisconsin, the 2012 Republican vice presidential nominee, who also dropped three points from CNN's last survey. Former Arkansas Gov. Mike Huckabee, a 2008 GOP presidential contender, is at 10%, with New Jersey Gov. Chris Christie at 9% and longtime Texas Gov. Rick Perry, a 2012 White House candidate, at 8%.
Wisconsin Gov. Scott Walker and Sen. Ted Cruz of Texas each stand at 7%, with Sen. Marco Rubio of Florida at 6%. Former Sen. Rick Santorum of Pennsylvania, a 2012 Republican presidential candidate who battled eventual nominee Mitt Romney deep into the primary calendar, is at 2%. Taking into account the poll's sampling error, everyone other than Santorum is within striking distance of the top spot.
The poll also asked Republicans for their second choice for the nomination.
"But the pattern of back-up picks is just as murky as the preference for the top spot, says Holland. "If Bush doesn't run – something his own mother would like to see- no single candidate benefits, with Christie, Ryan and Rubio all picking up two points of support."
What if Christie doesn't run due to the George Washington Bridge controversy?
The poll indicates Bush would be the biggest beneficiary, but he gains just three points of support with Christie on the sidelines. Paul is the biggest beneficiary if Cruz doesn't run (a net gain of three points for Paul with Cruz out of the race), and Paul returns the favor, with Cruz gaining three points if Paul is not in the race. Cruz, however, is not the obvious heir apparent to the Paul voters, as some of Paul's supporters would turn instead to Walker, Huckabee or Rubio, all of whom gain two points with Paul out of the nomination hunt.
"If Ryan stays on Capitol Hill to polish his portfolio on an important committee, Paul and Bush gain the most," Holland adds. "It all adds up to a tangled - and very hypothetical - picture of what may come in 2015 and 2016."
In its early stages, the race for the Republican nomination already has a different feel than previous nomination battles the past couple of decades.
"It's just a free for all in a party known for having a relatively orderly succession process. Most interesting to me is the top of the pack – Rand Paul and three guys who for different reasons might not run – Bush, Ryan and Huckabee. Add them up and that's 35% in this poll. Which makes a wide open race even more fun and unpredictable," King adds.
One more caveat: With the start of the 2016 primary and caucus calendar still more than a year and a half away, polls at this early stage in a presidential cycle are often influenced by name recognition.
The CNN poll was conducted May 2-4 by ORC International, with 1,008 adult Americans questioned by telephone. The survey's for questions regarding the Democratic and GOP presidential nominations is plus or minus 4.5 percentage points.