Washington (CNN) Even before Clinton declared his presidential bid earlier this year, more than 60% of Democratic senators had already endorsed her run.

Here is the latest list of senators backing Clinton:

Sen. Tammy Baldwin of Wisconsin - Signed a letter with all other female senators backing a Clinton run

Sen. Richard Blumenthal of Connecticut- Told CNN at a 2014 University of Connecticut event that he "would support her when and if she" runs.

Booker told NBC News that there are "few candidates in history" as qualified as Clinton. "There are few candidates in history who are as qualified or ready for the job of president as Hillary Clinton. I'm excited about her candidacy and her vision for our country," Booker said.

Sen. Barbara Boxer of California - Signed a letter with all other female senators backing a Clinton run

Sen. Maria Cantwell of Washington - Signed a letter with all other female senators backing a Clinton run

Sen. Ben Cardin of Maryland - Headlined of Maryland- Headlined a December 2014 fundraiser organized by Ready for Hillary

Sen. Bob Casey of Pennsylvania - At a 2014 event in Philadelphia, Casey - At a 2014 event in Philadelphia, Casey told CNN that it was too early to talk about Clinton 2016. "I'm not going to get into that," he said. But after Clinton announced her run, he emailed supporters to say , "Having served with her in the Senate, I know she has always been a strong advocate for the middle class and I'm confident she will work tirelessly to ensure that Pennsylvania families have the chance to get ahead and stay ahead."

Sen. Chris Coons of Delaware - Announced on CNN's "New Day" on Tuesday that he was backing Clinton, several weeks after homestate favorite Vice President Joe Biden declined to run again.

Sen. Dick Durbin of Illinois - Headlined of Illinois - Headlined a June 2014 fundraiser organized by Ready for Hillary

Sen. Dianne Feinstein of California - Signed a letter with all other female senators backing a Clinton run

Sen. Al Franken of Minnesota - The senator of Minnesota - The senator told MSNBC this in December 2014: "I think that I'm ready for Hillary. I think that we've not had someone this experienced, this tough, and she's very, very impressive." Franken has also expressed support through Ready for Hillary.

Sen. Kirsten Gillibrand of New York - Signed a letter with all other female senators backing a Clinton run

Sen. Martin Heinrich of New Mexico- Headlined of New Mexico- Headlined a July 2014 fundraiser organized by Ready for Hillary

Sen. Heidi Heitkamp of North Dakota - Signed a letter with all other female senators backing a Clinton run

Sen. Mazie Hirono of Hawaii - Signed a letter with all other female senators backing a Clinton run

Sen. Bill Nelson of Florida - Nelson reportedly called Clinton in December 2014 to urge her to run. "It's time for a woman," of Florida - Nelson reportedly called Clinton in December 2014 to urge her to run. "It's time for a woman," he told The Tampa Bay Times . "I'm all for Hillary."

Sen. Tim Kaine of Virginia - Headlined of Virginia - Headlined a May 2014 fundraiser organized by Ready for Hillary

Sen. Amy Klobuchar of Minnesota - Signed a letter with all other female senators backing a Clinton run

Sen. Patrick Leahy of Vermont - of Vermont - Told Vermont Public Radio this in June 2014: "I told her if she decided to run I would support her and would be willing to do whatever she likes. I've made no secret of that ever since then."

Sen. Joe Manchin of West Virginia - He of West Virginia - He told Politico in January 2014 that he wants Clinton to run. "I don't know if there's anyone more qualified. I've seen it all," he said.

Sen. Claire McCaskill of Missouri - Signed a letter with all other female senators backing a Clinton run

Sen. Barbara Mikulski of Maryland - Signed a letter with all other female senators backing a Clinton run

Sen. Patty Murray of Washington - Signed a letter with all other female senators backing a Clinton run

Sen. Brian Schatz of Hawaii - of Hawaii - Tweeted Monday morning that he was backing Clinton in 2016.

Sen. Charles Schumer of New York - The outspoken senator has gone as far to say that of New York - The outspoken senator has gone as far to say that he would bet on Clinton running in 2016

Sen. Jeanne Shaheen of New Hampshire - Signed a letter with all other female senators backing a Clinton run

Sen. Debbie Stabenow of Michigan - Signed a letter with all other female senators backing a Clinton run

Sen. Mark Warner of Virginia - Headlined of Virginia - Headlined a July 2014 fundraiser organized by Ready for Hillary

Sen. Elizabeth Warren of Massachusetts - Signed a letter with all other female senators backing a Clinton run

Sen. Sheldon Whitehouse of Rhode Island- of Rhode Island- Told The Hill in January 2014 that he was backing Clinton.

Not all senators, however, are ready to endorse Clinton this early. Delaware Sen. Tom Carper has side-stepped questions about Hillary Clinton 2016, largely because of uncertainty around whether Vice President Joe Biden -- a Delaware native -- would run. Pennsylvania Sen. Bob Casey told CNN last year that it was too early to endorse.

Here is the list of not yet and nos to Clinton 2016:

Sen. Sherrod Brown of Ohio - In a June of OhioIn a June interview , Brown said he wasn't "on board with anybody" after being asked about Clinton 2016.

Sen. Thomas Carper of Delaware - The senator of Delaware - The senator told The Hill in 2014 that "It's entirely, entirely too early to be talking about anybody running for president."

Sen. Bernie Sanders of Vermont - The independent senator is Clinton's strongest primary challenger.

Some senators have been unclear about their support of Clinton in 2016. The best example is Senate Majority Leader Harry Reid.

Reid sent a fundraising email through Ready for Hillary in 2014 and regularly speaks highly of the Clintons. But he has not directly said that he is support her possible run.

Here is the list of senators whose support is unclear:

Sen. Michael Bennet of Colorado - The Colorado Democrat sent an email through Ready for Hillary in 2014, but to date, has not made it clear that he would back her run in 2016.

Sen. Joe Donnelly of Indiana

Sen. Angus King of Maine - The Maine senator has not said outright that he isn't backing Clinton, but in a post-election interview with MSNBC, the independent senator who caucuses with Democrats of MaineThe Maine senator has not said outright that he isn't backing Clinton, but in a post-election interview with MSNBC, the independent senator who caucuses with Democrats said , "I think that is going to be a difficulty for someone like Hillary Clinton, who has tremendous experience and background, but she's going to have a hard time saying, 'Oh, I'm a new person.'"

Sen. Ed Markey of Massachusetts

Sen. Robert Menendez of New Jersey

Sen. Jeff Merkley of Oregon

Sen. Chris Murphy of Connecticut

Sen. Gary Peters of Michigan - Clinton endorsed Peters in 2014 and although Peters hinted at Clinton's future, he didn't outright endorse her. "Whatever she does, she is going to be really great at it in the future," he said at the event with Clinton.

Sen. Jack Reed of Rhode Island

Sen. Harry Reid of Nevada

Sen. Jon Tester of Montana - After losing the chamber in 2014, the Montana Democrat was named chairman of the Democratic Senatorial Campaign Committee through 2016.

Sen. Tom Udall of New Mexico

Sen. Ron Wyden of Oregon