Whatever you blame Bush for, the rise of ISIS in Syria and Iraq are squarely Obama's doing.
Bullshit. Obama might not have handled things terribly well, but Bush bears most of the blame here. Let's look at the first issue: former prime minister Nouri al-Maliki. Maliki pursued a divisive, sectarian agenda that caused the country to split along religious lines. Could Obama have done more to influence Maliki to be inclusive? Maybe. But who created him in the first place? That's right- George W. Bush. Maliki was brought to power in 2006 with extensive US involvement and support. If Maliki's politics are to blame, then Bush is ultimately the one to blame for Maliki.
Second Issue: withdrawal of US forces from Iraq. Damn you, Obama! Except wait a minute, who was it who approved a Status of Forces Agreement with Iraq that called for all U.S. troops to leave in 2009... hm, it'll come to me... oh, that's right, it was BUSH! Maybe Obama could have pushed harder to keep a residual force, but he wasn't able to get an agreement. Turns out, he couldn't negotiate with Maliki. The guy, you will recall, put in power by the Bush administration.
Third Issue. These ISIS guys. Where do they come from? They're pretty badass, they act more like an occupying army than a terrorist organization. Turns out, there's a reason for that- they include a whole bunch of former Iraqi Army officers, who went to military academy and everything. Iraqi army officers who joined the insurgency after the Iraqi Army was disbanded by, wait for it... George W. Bush. Disbanding the Iraqi army was arguably the stupidest move of all, possibly even stupider than invading. It took the only force capable of holding the country together, destroyed it, and then then turned a bunch of disgruntled, unemployed soldiers and military officers loose to create an insurgency.
Fourth, Iraq invasion. It should be pretty obvious where the blame for that lies.