We know it is Congress that passes tax and spending legislation. So why does Trump blame Obama for increasing US debt?

trump knows nothing about this country.

And he knows nothing about how the government works.

And he's yet to read the Constitution.

It’s because he raised the debt in a year and usually accuses others of stuff he himself is doing.

Because that is exactly what narcissistic con men do. When things are going good it is all because of them and when things are all bad it is all about the other guy. American politics have absolutely nothing to do with the truth anymore, I'm not sure if they ever did. As long as people value partisanship over the health of the country we are screwed.

President proposes budgets and they can't become law without his approval. With Dims holding filibuster power in the Senate, only a budget that Obama approved could possibly pass. Thus, the continuing resolutions of 2010 through 2015 all perpetuated the deficits set up when Dims controlled all from 2008 and 2009 -- huge deficit years.