The problem is he can't legally.
And the right wing propaganda machine is too good about putting out lies so people vote against their own interests.
Plus the Republicans have the house Gerrymandered to where they don't need a majority of the popular vote to get a majority of the seats.
And the Senate gives the same number of votes (2) to sparsely populated red states like Wyoming with less than 600,000 people as it does to big blue states like California with 35 million people.
So overall the right wingers have far more power in congress than their numbers would suggest.
Then, if the Dems do get a working majority the billionaires like the Koch brothers step in and buy a few seats.
What a Democratic president really needs is an informed electorate that will give a Democratic President the kind of majorities that Roosevelt and Johnson had.
In 1937 under Roosevelt there were 75 Democratic Senators and 333 Democrats in the House.
And in 1965 under Johnson there were 68 Democratic Senators and 295 Democrats in the House.
http://www.infoplease.com/ipa/A0774721.html
It's no mistake that it was during this time that real meaningful progressive legislation like Social Security, Medicare, and Civil Rights got passed.
Legislation that has helped, not hindered the country.
That's what we need again.