Republicans are full of piss and vinegar from the shellacking they dished out to Democrats last November. They did very well nationally, reclaiming the majority in the U.S. Senate and upping their seat totals in the U.S. House of Representatives to 247, 29 more than the 218 votes needed to pass a bill. What happened in Washington was also echoed in statehouses across the nation, including Ohio, where the GOP now enjoys the largest number of House seats—65 out of 99—since 1966, when Ohio started electing House members by single-member districts. GOP control of the Ohio Senate remains lopsided at 23-10.

GOP leaders in Washington can’t wait to take on the White House over a raft of issues, starting with the XL Keystone Pipeline and extended to many others, most importantly, monkey-wrenching President Obama’s signature legacy achievement, The Affordable Care Act. But President Obama, now term-limited with no other reelection campaign to manage, has one tool Republicans can’t overcome: his veto pen.

With a new Congress now in session, Republican majorities in both the House and Senate are planning to deliver one distasteful bill after another to the White House, if they can first approve them in their respective chambers. And while they have the votes to do so in the House, where Ohio Congressman John Boehner was just elected again to be speaker. But Majority Republicans in the Senate will have to labor to pass their agenda, as Democrats will surely force them to get 60 votes, five votes more than their majority, to pass any floor votes. And even if they do convince five or more Democrats to break ranks, the light at the end of the tunnel is really Obama’s veto pen glaring back at them.

As an overture to the many battles that lie ahead in the new year, the White House said on Tuesday that President Obama would veto legislation that approves construction of the Keystone XL pipeline if it passes Congress. The pipeline and the Affordable Care Act are high priorities for Republicans, who want to pass the former and disable the latter. What happens when an unstoppable force meets an immovable object? In the case of Washington politics, it remains to be seen if GOP efforts to undue much of what the president has accomplished over the last six years is indeed unstoppable. What’s more certain is that the immovable object—Obama’s big swinging veto pen—is indeed immovable.

For a bill to become law without the President’s signature, a two-thirds majority vote in each house is needed. A review of such actions shows Congress has overriden a Presidential veto less than 10 percent of the time. The year 1845 is significant since it marks the first year Congress first overrode a presidential veto. For perspective, President Obama has only vetoed two bills in his presidency so far. For historical comparison, President Franklin D. Roosevelt used his veto pen 372 times. Second to Roosevelt, was Grover Cleveland, who used his 304 times. Presidents Ronald Reagan and Bill Clinton used their veto pens 39 and 36 times, respectively. Even George W. Bush only used his authority 11 times.

Clearly, President Obama will add to this puny number as he concludes his final two years in office if Republicans, giddy with power, keep trying to derail, delay or deny his agenda.