The outcome is slightly uncertain because Republicans, who hold a 53-47 majority, face united Democratic opposition − and the defection of at least two of their own members.Start the day smarter. Get all the news you need in your inbox each morning.

Democrats are using Monday's "vote-a-rama" to highlight cuts they say President Trump's megabill will make to Medicaid, SNAP and rural hospitals -- and to hammer in the tax cuts they say this bill gives to the wealthiest Americans. So far, Republicans have defeated all Democratic efforts to modify or reconsider the bill.