Populist Reform of the Democratic Party

Kevin Zeese is quoted as saying:

Yes, Obama signs the agreement (it's not a treaty) before Congress sees it, but the mere signing doesn't implement it. TPP doesn't affect trade one iota unless and until Congress approves it.

It's the same as when the Obama administration developed its proposal for the stimulus. Congress has the power over taxes and spending just as it does over foreign commerce, but Obama's sending a proposed stimulus bill to Congress didn't violate that power. Nothing in the ARRA changed any tax rate or spent one dollar until it was enacted into law through the normal process.

I think that, with the ARRA, Obama developed it largely without Congressional input, whereas with the ACA Congress had a much bigger role in the drafting. That's just a tactical choice to be made by the President (whoever's President).