Was Nixon convicted?
Nixon wasn’t even impeached, let alone convicted.
Nixon resigned. He considered it the best thing to do for the country given the circumstances.
“Was Nixon convicted?”
Nixon resigned before the Senate voted on conviction. He almost certainly would have been convicted had he not resigned.
Remember Nixon’s own party in Congress turned against him making the job of his Democrat opponents easier. So far the Democrats are united in defending and protecting Obama.
With respect to the politics of impeachment and conviction, Boehner and Cantor have no stomach for using the appropriations power of the House to reign in spending. It is hard to envision House Republicans who consistently cave to Obama on any contentious issue bring up articles of impeachment, much less voting to impeach. In fact, they are failing to take advantage of the public furor over Obamacare (look at the failure to rip Sebelius apart today) and seem to be preparing to cave on immigration.
Moving to the Senate most of the 25 Republicans who opposed Ted Cruz on the Obamacare cloture vote do not have the stomach to impeach Obama. It is difficult to imagine any Democrat or Independent Senator voting to convict him.
The press of the 1970’s was almost united in its opposition to Nixon and support for impeachment. Today’s mainstream press would almost certainly work to protect Obama.
In summary, don’t count on impeachment and conviction to remove Obama from office.