Investors and analysts have been waiting for at least three years to see General Motors' (NYSE:GM) shares get some momentum. But not too many would have predicted that the General's stock would jump almost 20% in just three months.

That's exactly what has happened. November's election surprise has had all kinds of repercussions in markets around the world. Not all automakers have seen this kind of increase -- rival Ford Motor Company's (NYSE:F) stock is only up about 7.25% --  but GM's shares have done quite well.

A red Chevrolet Camaro burning rubber on a drag strip.

GM's shares have burned rubber since the election. Image source: General Motors.

The surprise election of President Donald Trump gave the auto sector a boost. That itself might have been something of a surprise, given that, as a candidate, Trump heaped scorn on the Detroit automakers (Ford in particular) for their Mexican factories. 

But while President Trump has pushed GM, Ford, and Fiat Chrysler Automobiles (NYSE:FCAU) to move more production to the United States, he has also made a point of listening to their concerns. 

In particular, Trump has been receptive to the idea of loosening Obama-era fuel-economy regulations. Fuel-economy rules are currently set to tighten considerably over the next few years. Automakers will have to add technology to their trucks and SUVs to meet the stricter rules. That will add costs, and with gas prices still low, it's unlikely consumers will be willing to pay big premiums for fuel efficiency. 

That threatens to dent Detroit's profit margins. But it's looking likely that Trump's administration will give GM and its hometown rivals some breathing room. 

GM Chart

GM data by YCharts.

The election of Donald Trump has helped GM's shares more than those of most rivals, because GM sells more trucks and SUVs in the U.S. than most rivals. But part of the reason for GM's surge is simply that GM is performing well overall, its outlook for 2017 is more upbeat than those of many rivals, and investors are noticing.

GM earned a record $12.5 billion in operating income in 2016, up 16% from the year before. Its operating margin of 7.5% was up from 7.1% a year ago, and its $166.4 billion in revenue was an all-time record for the General. 

What's more, even with the U.S. market likely at a plateau and China's market slowing, GM's outlook for 2017 is upbeat. That's because GM is in the midst of launching a range of all-new crossover SUVs. 

A red 2018 Chevrolet Equinox.

The all-new 2018 Chevrolet Equinox should give GM's sales and profits a boost. Image source: General Motors.

The Chevrolet Equinox and Traverse, GMC Acadia and Terrain, and Buick Envision and Enclave are among its most profitable products. (The Equinox is also one of its best-sellers.) The all-new versions are much improved and look set to deliver even fatter profit margins along with higher overall sales -- even in a flat market.

Even though GM's shares have surged, there's a good argument that they're still fairly cheap. GM's price-to-earnings ratio is just over 6, below its historical multiple (during good times) of about 10 times earnings. On top of that, GM's rock-solid and conservative dividend is yielding about 4%. Given the growth course CEO Mary Barra has set for the General, I think it's still worth a close look at current prices.