PPP's monthly look at the 2016 Republican field for President finds essentially a 4 way tie at the top- Marco Rubio has 16%, Jeb Bush and Chris Christie 15% each, and Rand Paul 14%. Paul Ryan at 9%, Ted Cruz at 7%, Rick Santorum at 5%, Bobby Jindal at 3%, and Susana Martinez at 1% round out the potential candidates we tested.
It's now been almost 6 months since we started doing regular polling of the 2016 race. The only candidate who's shown any real momentum over that period of time is Paul, whose support has doubled from 7% to 14%. Rubio's shift from 18% to 16%, Bush's from 12% to 15%, and Christie's from 14 to 15% are all within the margin of error. It is worth noting though that this is the first time Rubio hasn't held at least a 4 point lead over the other Republican contenders.
There hasn't been much movement on the Democratic side either. Hillary Clinton leads with 63% to 13% for Joe Biden, 4% for Andrew Cuomo, 3% for Mark Warner and Elizabeth Warren, 2% for Martin O'Malley, and 1% each for Kirsten Gillibrand, Deval Patrick, and Brian Schweitzer. Clinton led Biden 61-12 when we started polling on this in December. Clinton has at least 58% support with liberals, moderates, men, women, whites, African Americans, Hispanics, young voters, and seniors- in other words every key segment of the Democratic electorate.
Chris Christie continues to be the only potential Republican candidate who polls competitively with Clinton, trailing her just 47/44. Christie has a 40/32 favorability with Democrats, making him the only potential 2016 contender with any crossover appeal. Clinton holds identical 10 point leads at 51/41 over Paul and Rubio.
Clinton is on average about a 10 point stronger general election candidate than Biden would be. He trails Christie 49/40 in a hypothetical match, including 51/29 with independents. And he leads Paul (46/44) and Rubio (46/45) by pretty tight margins.
Full results here