The main purpose of this legislation, known as the Middle Class Savings Act, is to update the tax treatment of capital gains by aligning the income thresholds for capital gains tax brackets with current income tax brackets. This aims to ensure that individuals who earn capital gains are taxed fairly in relation to their overall income. Key provisions of the Act include specific adjustments to the income thresholds for capital gains tax brackets. The bill raises the income limits for various capital gains tax rates.