WASHINGTON -- Fresh off a re-election win, Democratic Rep. Tim Walz is taking on the party establishment in asking for support to be the top Democrat on the Veterans Affairs Committee.

Seniority is a big factor in leading committees in Congress, which means Walz's quest will be an uphill battle. Democratic leader Rep. Nancy Pelosi is backing the most senior Democrat on the committee, Florida Rep. Corinne Brown.

Walz, a 50-year-old retired command sergeant major in the Army National Guard who just won his fifth term, says he has a keen idea and track record of understanding what veterans need. He has served on the VA committee since 2007 and said the current system was "in crisis."

In a letter Walz sent to fellow House Dems late last week, he said caring for men and women in uniform and their families "has been my number one priority since being elected to the House of Representatives."

Walz cited fighting the scourge of veteran suicide, ensuring veterans exposed to Agent Orange and other toxins receive appropriate care and benefits, and enhancing mental health services to veterans suffering from PTSD as accomplishments.

"Our VA system is in crisis and now, more than ever, Democrats need a strong, respected voice to address these problems head on," he wrote.

Walz's office said Monday the congressman was unavailable for an interview on this topic. Members of Congress return Wednesday to finish work through December before the new Congress starts January.

Walz's primary opponent, Rep. Brown, has served on the VA committee for 22 years.

In a competing letter she also wrote to fellow Dems last week, Brown cited bringing a new VA outpatient clinic to her district and bringing "tens of millions of dollars in funding for the Gainesville VA Medical Center" as reason she should be chosen over Walz.

If selected, Brown would be the first African-American to serve as ranking member of the committee, she said in the letter.

Members vote on committee leadership posts in the next couple weeks.

In a letter sent to Democrats on Monday, Pelosi said seniority should not be the only factor in choosing leaders.

"There was enormous respect for the senior Member, but our colleagues viewed seniority as a consideration not a determination," she wrote.