That's not how marginal income tax rates work. If your taxable income is, say, $250,000 and you are married filing jointly, then you are in the 35% bracket, but you don't pay 35% on the entire $250,000, because the 35% is your top marginal rate. It's the amount you pay on every dollar above the threshold for that bracket (in this case $231,250.

The total you would pay, excluding any credits, would be $59,394, making your effective tax rate (59,394/250,000) about 23.7%.