Sen. Elizabeth Warren wants the next debate in Congress on student loans to focus on helping borrowers refinance their debt.

The Massachusetts Democrat planned to file a bill Tuesday that would open the door for potentially millions of borrowers of earlier federal loans to refinance that debt at the same rate that current recipients can get. Undergraduates, for example, qualify for loans at a 3.86 percentage rate.

The bill is part of a larger effort by Senate Democrats to focus on college costs leading to the November election.

Last year, Congress reached a bipartisan deal that ties federal student loan interest rates to financial markets for students who take out loans, starting last July.

The bill would be paid for by raising taxes on wealthy Americans. Passage could be difficult.