WASHINGTON—Both houses of Congress endorsed the idea of tax increases for millions of Americans Thursday as Democrats pressed ahead with budget plans that would allow some or all of President Bush’s reductions to die after he leaves office.

All three major presidential candidates interrupted their campaigns to cast votes on the budget planning, which is non-binding but highlights the difficult choices facing the next president and Congress. Binding votes on the expiring Bush tax cuts will be left to his successor and the Congress that’s elected in November.

The candidates also wanted a chance to vote for a one-year ban on pork-barrel projects, though that late-night Senate effort seemed doomed to defeat. The practice of inserting “earmarked” spending into legislation is seen as a birthright by lawmakers in both parties—and a right under the power of the purse awarded to Congress by the Founding Fathers.

As for the $3 trillion federal budget plans, the House version would provide generous increases to domestic programs but bring the government’s ledger back into the black by letting all of Bush’s tax cuts expire at the end of 2010 as scheduled. That five-year plan passed the House on a 212-207 vote with Republicans unanimously opposing it over what they argued was $683 billion in tax increases.

In the Senate, John McCain of Arizona, the Republican presidential nominee-in-waiting, voted to extend the full roster of tax cuts, which he opposed seven years ago as being tilted in favor of the wealthy. Democratic rivals Hillary Rodham Clinton of New York and Barack Obama of Illinois both voted against them.

Clinton and Obama did vote for $340 billion in tax cuts over five years for middle- and higher-income taxpayers, investors and people inheriting businesses and big estates.

But they joined with Democrats and a couple of maverick Republicans to reject, 52-47, an additional $600 billion in extensions of income tax rate cuts, more generous estate tax cuts and relief from the alternative minimum tax.

Republicans hope to use the votes as fodder for the heated presidential campaign and for congressional races. Lawmakers in both parties also were put on record for when the tax cuts actually expire in three years.

Said Republican Rep. Jim McCrery of Louisiana, “Democrats are quietly but very assuredly paving the way for a massive, economy-choking, tax increase.”

Separately, the moratorium on pet spending projects seemed headed for defeat despite the backing of all three of Bush’s potential successors.

Earmarks have exploded in number and cost in recent years, accompanied by charges of abuse and public outrage over egregious examples like the proposed “bridge to nowhere” in Alaska.

“Too many senators have confused the founding fathers of the earmark favor factory with the Founding Fathers of the United States of America,” said Sen. Tom Coburn, R-Okla.

On the subject of tax cuts, Democrats in the House defeated a GOP plan that would have extended Bush’s reductions — and went further by eliminating the alternative minimum tax, which was originally designed years ago to make sure rich people pay at least some tax but now threatens more than 20 million additional taxpayers with increases averaging $2,000.

Some 38 mostly moderate Republicans voted against their party’s plan, which would have made cuts in popular programs like Medicare, housing, community development and the Medicaid health care program.

Congress’ annual budget debate involves a nonbinding resolution that sets the stage for later bills affecting taxes, benefit programs such as Medicare, and the annual appropriations bills. Unless such follow-up legislation is passed, however, the budget debate has little real effect and is mostly about making statements about party priorities.