Should ObamaCare be defunded? Absolutely. It is an economic disaster and will be a medical disaster, as well as destroying the Constitution's protections of American citizens from the unbridled power of the federal government.
For that matter, President Obama deserves to be impeached for arbitrarily waiving laws he doesn't like, in defiance of his oath of office and the Constitution's separation of powers.
Chief Justice John Roberts also deserves to be impeached for his decision upholding ObamaCare, by allowing the government's taxing power to override all the Constitution's other provisions protecting American citizens from the arbitrary powers of government.
But, for the same reason that it makes no sense to impeach either President Obama or Chief Justice Roberts, it makes no sense to attempt to defund ObamaCare. That reason is that it cannot be done. The world is full of things that ought to be done but cannot in fact be done.
The time, effort and credibility that Republicans are investing in trying to defund ObamaCare is a high risk, low yield investment.
Even if, by some miracle, the Republicans managed to get the Senate to go along with defunding ObamaCare, President Obama can simply veto the bill.
There is a United States of America today only because George Washington understood that his army was not able to fight the British troops everywhere, but had to choose carefully when and where to fight. Futile symbolic confrontations were a luxury that could not be afforded then and cannot be afforded now.