Scenario 1: George W. Bush veto's the bill. The Democratically controlled Senate spends the time between now and the fall elections beating GW and the Republicans over the head, eventually overriding the veto weeks before the election in a media enhanced blaze of saving America publicity. Months after the election the Supremes overturn the law, but the damage has been done, Dems are firmly in control of Congress. No conservative judges on the court. No conservative agenda going anywhere.
Scenario 2: He signs the bill as soon as he can. Shuts up his critics. Makes sure his legal team "defending" the law understands the end game. The court strikes down most if not all of the law. Takes the issue away. November elections go the way of the Pubbies. More conservative judges are seated. The country continues it's move to the right.
Your last premise is unsupportable. It is not moving to the right. Conservative bastions such as North Carolina and Texas are being overrun by liberalism. California, which since 1956 was a reliable Republican state (excepting 1964), is now reliably Democrat. Many other examples abound that the country is moving left and both parties are moving towards Statism.