(CNN) Before Sen. Bernie Sanders sets out on the first campaign swing of his second presidential bid, he has some business to mind to in Washington.

On Monday night, Sanders will face questions from voters at a CNN town hall ahead of a dramatic week that will see President Donald Trump meet with North Korean leader Kim Jong Un, the public testimony of the President's former lawyer, Michael Cohen, and the expected unveiling of House Democrats' new Medicare for all bill.

The Sanders campaign is barely a week old, but the forces that will either carry him to greater heights -- starting with an electrified base of small dollar donors and, as of Sunday night, one million online pledges of support -- or keep a lid on his appeal, are already making themselves heard. Trump's re-election campaign welcomed Sanders to the race with three straight days of attacks wrapped in fundraising asks, warning that the Vermont independent's ascendance would usher in an era of "full-blown socialism."

There is a different conversation happening on the Democratic side, which been almost unerringly collegial as the candidates consider the political price -- too hefty at this point -- of being seen to undermine any potential future nominee. Sanders' entry might have sparked anew old intra-party skirmishes on social media, but the contestants are still playing nice.

California Sen. Kamala Harris in a fundraising email last week wrote that she is "excited to welcome my friend and colleague (Sanders) to the growing field of incredible Democrats who have entered this race." And the Progressive Change Campaign Committee, which has endorsed Massachusetts Sen. Elizabeth Warren, greeted Sanders with a similar message and has since described him and Warren as a "one-two punch."

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