Washington (CNN) -

Republican National Committee Chairman Reince Priebus formally launched his re-election campaign Thursday in a letter and YouTube video sent to the 168-member committee.

In the letter, provided to CNN by a GOP source, Priebus touts his fundraising success since taking over the committee and its $24 million debt burden in early 2011.

And in a warning shot to any potential challengers, Priebus writes that he has the votes of more than 150 RNC members locked down. Only 85 votes are needed to win the chairmanship.

Former Rep. J.C. Watts and former RNC Chairman Michael Steele have both hinted at challenging Priebus after Republicans failed to defeat President Obama in November, but neither Republican has taken any serious steps toward mounting a campaign.

Read Priebus' full letter to the RNC below:

I am formally announcing my campaign for a second term as RNC Chairman today. As I mentioned to you be email just before Thanksgiving, I appreciate the strong support by so many of the RNC members. I am humbled to have over 150 members pledge their public endorsement to me for a second term.

This is not a decision I made lightly, but we have unfinished business and our country and Party need our leadership over these next two years. We were able to accomplish a great deal these past two years, and I have not forgotten just how much work we had to do when I was first elected. Over those two years we lifted the RNC out of the over $24 million of debt, we restored donor confidence and fielded one of the strongest Republican ground games in the history of our Party.

With that said, we have to do more. That is why I am running. I am running to build upon those accomplishments so that we can continue to grow the Party and unite as a Party based on our strong conservative principles and love of country. Just like two years ago, there is much to do, but I am excited about it and know we can accomplish our goals together.

My bid for reelection is a continuation of my pledge to work day in and day out for our country and our Party. Please know that I am grateful for each and every one of you. I look forward to talking with you over the next weeks and visiting with you at the RNC Winter Meeting in Charlotte, North Carolina.

Together, we will move our Party forward and improve upon all that we accomplished over the past two years.

Again, I want to thank all of you for your support and all of your hard work.

God Bless!

Reince